The original version of Superman's origin had him becoming a superhero when full grown. However, in 1945 DC introduced Superboy as an addition to Superman's backstory, retconning in prequels and earlier meetings with DC characters.At the start of the Silver Age, one story, in Adventure Comics #247 (April, 1958), introduced the "Legion of Super Heroes", a trio of super-powered teenagers from the future who committed many acts of Super Dickery while initiating Superboy into their club — with the best of intentions, really. The trio became popular enough to be seen again, as Superboy began traveling in time to team up with them, and the other new members they'd recruited.The Legion gradually became more prominent in Adventure Comics (which at the time was a second Superboy book) and took over as the main feature with issue #300 (September, 1962), reducing Superboy to supporting character status on what used to be his comic book. They are remembered for their wide-eyed idealism, not to mention corny touches — their clubhouse was designed to look like a crashed rocket. How they all fit inside was never explained. However, their series was surprisingly sophisticated for the Silver Age; with one of the earliest comic book characters Killed Off for Real in Ferro Lad (and, for that matter, one of the earliest comic book resurrections with Lightning Lad), a trial for a Legionnaire killing in self-defense, and dealing with Fantastic Racism even before Star Trek did.To become a member, you had to demonstrate at least one superpower not dependent on devices. Thus, telepathy, Saturn Girl; electricity powers, Lightning Lad; magnetic powers, Cosmic Boy, and so on. Applicants with ridiculous powers (and some members of the Legion proper had pretty ridiculous powers) were consigned to the Legion of Substitute Heroes, who included Chlorophyll Kid (ability to make plants grow really fast), Stone Boy (ability to turn into an inanimate statue), Color Kid (ability to... change the color of things), and Double Header (whose name speaks for itself).At the end of the Silver Age, the Legion's slot was swapped with Supergirl, leaving Supergirl as star of Adventure Comics and the Legion as a backup in Action Comics. After the retirement of editor Mort Weisinger, the Legion was reduced to an occasional backup in Superboy. Dave Cockrum, who would go on to design many members of the Bronze Age incarnation of the X-Men, became the Legion's regular artist, and started redefining their look. With this, their popularity started to inch upwards again, and eventually, Superboy became Superboy and the Legion of Super-Heroes.This incarnation used plenty of the Soap Opera-style storytelling that was popular in the days of X-Men and Teen Titans, but kept on a level of solid yet unexciting sales, even after they booted Superboy out of his own book. This changed in the early '80s, with the Paul Levitz/Keith Giffen Legion. Classic stories like "The Great Darkness Saga" appeared during this run, but it was interrupted halfway through by the Crisis on Infinite Earths.Since the entire premise of the Legion was centered around Superboy, and Superboy no longer existed in the Post Crisis universe, the history and continuity of the series didn't work any more. DC's initial patch was to say that, during the Crisis, one of the Legion's foes, the Time Trapper, had created a pocket dimension containing an Earth where there was a Superboy. However, this issue kept coming up over time, with more and more patches needed just to keep things together.Eventually, Keith Giffen took over the book, along with fans-turned-writers Tom and Mary Bierbaum, and the series really jumped into the Dark Age with the "Five Years Later" Time Skip. Earth is ruled by alien invaders. One character was retconned into an Applied Phlebotinumtranssexual, and another into a shapeshifter who only thought he was the character. The Legion are actually clones — unless the other, younger Legion (Batch SW6) that were discovered in People Jars are the clones, as one might think at first. The moon was destroyed, followed by the Earth itself.Eventually, a combination of continuity issues and low sales brought DC to the point where they said "screw it" and decided to reboot the series altogether. In 1995, as part of the Zero HourCrisis Crossover, Mark Waid and Tom McCraw wrote the first issue of an all-new all-different Legion. Some of the sillier characters were pruned, and others were introduced to fill the gaps. This incarnation of the Legion was a youth corps run by The Federation, which was just forming as the series began, to symbolize its member worlds and species working together. (Although they were frequently dismissed as either a publicity stunt or a "teenage death squad".) This version sidestepped the Superboy issue by being inspired by the 20th century's age of heroes in general (although the Post-Crisis Superboy did become a member). The new version attempted to distill all of the Legion's history to date, while adding its own twists — some of which didn't work that well (Sneckie) Still, this version lasted until 2004 with a few writer changes and ReTools; then, they were wiped out (or at least detached from the main line of DCU history) during the build up to the Infinite CrisisCrisis Crossover, and replaced with a third version — the "threeboot" Legion.This version, also introduced by Mark Waid, brought back many of the more idealistic elements, including the Something Person names, while going for a more complex universe. In this incarnation, the Legion are firebrands and muckrakers in a future where those under 18 are almost entirely controlled by their parents and a paternalistic government; although only a chosen few are given flight rings (which are ridiculously expensive), anyone who follows their ideals is considered a Legionnaire. It also added twists to many of the characters; for instance, in this version, Colossal Boy is a member of a race of giants whose super-power is to shrink to six feet tall. (He prefers to be called Micro Lad.) Their inspiration this time is legends of superheroics as preserved in old comic books. Supergirl joined up about a year and a half into the series, having apparently made the trip during the "One Year Gap" in her own title (all DC books jumped forward a year after Infinite Crisis), and been given Laser-Guided Amnesia before she was sent back. On the other hand, the political aspects ("Eat it, Grandpa!") wore thin for some readers. This version lasted until 2009, when, despite fan favorite Jim Shooter taking over writing duties, it was unceremoniously cancelled with a rushed final issue written by "Justin Thyme".Recent stories post-Infinite Crisis have reintroduced The Multiverse and restored the original Legion, including Superman's past with them. This version first (re)appeared in the "Lightning Saga" Bat Family Crossover between Justice League of America and Justice Society of America and is the one currently appearing in DC Comics. As part of Final Crisis, Geoff Johns wrote a miniseries called "The Legion of Three Worlds" which dealt with all three versions (original, Zero Hour, and threeboot) of the Legion.From 2006 to 2008, an Animated Adaptation came along, taking the most iconic versions of all involved (but taking even more inspiration from the DCAU, despite, judging by Brainiac 5's being an android, not being in continuity with it.) See Here for that series.There is a character sheet.The comic book series starring the Legion (not counting oneshot issues like the Legion's origin) are:
The Legion started as guest stars in Superman-related comics. Their first appearance was in Adventure Comics in 1958. They became stars of that comic with issue 300.
Adventure Comics (1962-1969)
Action Comics as backups only (1969-1970).
An irregular series of backups in Superboy (1971-1973), along with a four issue reprint series in 1973 titled Legion of Super-Heroes (volume 1)
Superboy with issue 197 became the Legion's comic and was renamed to Superboy and/starring the Legion of Super-Heroes (1973-1980).
Renamed again to Legion of Super-Heroes (volume 2, 1980-1984).
Renamed to Tales of the Legion of Super-Heroes (1984-1985).
Legion of Super-Heroes (volume 3) (1984-1989). Overlapped Tales for a year, and then Tales switched to one year delayed reprints of this book.
The "five years later" version:
Legion of Super-Heroes (volume 4) (1989-1994)
Legionnaires (1993-1994) starred clones (sort of) of the Legion.
The reboot version:
Legion of Super-Heroes (numbering continues) (1994-2000)
Legionnaires (numbering continues, but the series is now just a second Legion comic with the same characters, no clones) (1994-2000)
Legion Lost (2000-2001)
Legion Worlds (2001)
The Legion (2001-2004)
The threeboot version:
Legion of Super-Heroes (volume 5) (2004-2009). #16-36 titled Supergirl and the Legion of Super-Heroes
The modern version, based on the original, appeared as guest stars in Superman-related comics since 2007. This overlaps the Threeboot, causing lots of confusion. Important stories and series include:
Lightning Saga (2007) (In JLA and JSA)
Superman and the Legion of Super-Heroes (2008) (in Action Comics)
In related series R.E.B.E.L.S., featuring Vril Dox II, an ancestor of Brainiac 5's from the 20th century, the earlier Dox makes a deal with Neron in exchange for knowledge, offering up not his own somewhat tarnished soul, but instead placing the debt on his bloodline and setting it to come due in "about 1000 years." After R.E.B.E.L.S. was canceled, a team of Legionnaires was sent back to the 20th century, leading to a meeting between Querl and his ancestor in which Vril mentioned Neron in a guilty sort of way... and then nothing came of it. It was implied, however, that the insanity of Brainiac 5's mother could be related to this deal.
Prior to this, a number of long-running subplots started during the TMK run were dropped unceremoniously because of the Zero Hour reboot. Some of these were quickly condensed into a panel or two in the final issue, but others were just forgotten. Most notably, Sussa Paka (formerly the villain Spider Girl) steals a mysterious sealed canister from the corrupt Earthgov branch of the Science Police (secretly under the control of the alien Dominators). On the run from the cops, she gets caught up in the Legion's battle to liberate Earth. Eventually, she shows up on the Legion's doorstep looking for protection, and immediately gets caught up in their problems. She grows fond of the team, and ultimately joins up, adopts a new name (Wave) and a new hair color... but events start cascading from there, and the actual contents of the canister that half the galaxy was ready to kill Sussa to get their hands are never revealed.
Absurdly Sharp Blade: The Persuaders atomic axe can cut through anything... even the force of gravity.
Abusive Parents: Apparition's absent father in the reboot certainly qualifies, having sold two of her three bodies to pay off his gambling debts. Dr. Londo at least in the Animated Series also qualifies. Timber Wolf's relationship with his father varies on continuity whether he was a bastard or a Papa Wolf. It was assumed before the reboot (in his solo series to be specific) he had a poor relationship with his father when the drug/Zuunium Rays Dr. Londo used on his son was slowly killing him. His reasoning with Gemini/Aria to going into the past (part of her power) which lead to his solo series was in fact to stop his father from beginning the Zuunium treatments which would lead to Timber Wolf's subsequent illness.
In "threeboot" continuity, Gim Allon comes from a race of giants all of whom have the power to shrink down to normal human size. To him, his power is to shrink, but everyone else sees it as growing. So most of his teammates persist in calling him "Colossal Boy," instead of his preferred name, "Micro Lad."
Similarly, Atom Girl doesn't take well to being called "Shrinking Violet."
Action Girl: Most girls in the Legion qualify. Shadow Lass/Umbra especially stands out.
After-Action Healing Drama: Once when the White Witch, Mon-El, and Ultra Boy rescued Dev-Em from enemies, they had to rush him to treatment for Kryptonite poisoning.
All There in the Manual: A number of pivotal events that occurred during the "five year gap" between the conclusion of Paul Levitz's 1980s run and the start of the Keith Giffen / Tom and Mary Bierbaum run, including things like the dissolution of the team, the death of several former members, and the general devolution of the entire galaxy into a Crapsack World, were never fully explained or explored in the comic itself. Many were given much deeper treatment in the Legion of Super-Heroes sourcebook for the defunct DC Heroes role-playing game, much of which took the form of an in-universe scrapbook of news clippings and diary entries.
All Just a Dream: Invoked to escape the restrictions imposed by the original "adult Legion" story from the 1960s. They, and a number of other "what if?" scenarios, were explained away as dreams induced in the mind of Ferro Lad's catatonic brother, Douglas Nolan.
Explicitly forbidden in most versions of the Legion's constitution. Any hero whose only powers are derived from an external source (like a belt, ring, or clothes) are not allowed to serve on the team. Examples include the first Kid Quantum (whose death led to the adoption of the rule in the first place, in the reboot version) and any member of the Green Lantern Corps.
On the other hand, flight rings and transsuits are assigned to all active Legionnaires to allow for flight, communication, and survival in the vacuum of space or in other hostile environments.
The Geoff Johns era briefly had Rond Vidar as a member, and his power was having a Green Lantern ring. Unless he got in under a technicality, this would indicate the rule wasn't in effect then.
Rond does have a special power, albeit a very minor one: He is completely impossible to hypnotize. Not difficult, impossible.
Ascended Fanboy: The Batch SW6 Legionnaires were so-named as a reference to a well-known fan and letter writer with a London SW6 return address.
Ascended Meme: Arm-Fall-Off Boy had been a joke in forums and comic book stores for over a decade before he made an actual appearance in Secret Origins.
Badass Family: The Ranzz Family. Garth, his sister Ayla, and his wife Imra. Unless you have a death wish, do not miss with Graym and Garridan Ranzz, Garth and Imra's twin boys.
Badass Normal: Karate Kid, who has no actual superpowers but has never run into any trouble with the Legion's traditional superpower requirement, presumably because nobody wants to say no to a guy who's demonstrated that he can put the absurdly overpowered Silver Age Superboy in a headlock.
Beware the Quiet Ones: Shrinking Violet in postboot continuity. She starts off as, well, a Shrinking Violet. Over time she is showing coming out of her shell, even going so far as to be elected team leader. Right after that, it's revealed that her increased confidence was the result of her coming under the influence of the Emerald Eye of Ekron.She completes a (temporary)Face-Heel Turn shortly thereafter and curbstomps her former teammates.
Beware the Silly Ones: Matter-Eater Lad as written by Keith Giffen and Tom and Mary Bierbaum. He was a shameless self-promoter and con artist and affected an air of extreme vanity, but was a bit of a Bunny-Ears Lawyer. Literally, in one case: he successfully manages to get former teammate Polar Boy freed from unjust imprisonment by employing the Chewbacca Defense and then quickly smuggling him off-planet before anyone recovers enough to realize they'd been bamboozled. It's also worth remembering that Matter-Eater Lad is basically a walking disintegrator who can annihilate anything he can get his jaws around.
In the Great Darkness Saga of The Eighties, the Legion faces Darkseid, still very much one of these. The team is forced to call in every available ally in order to deal with him... and the three billion Superman analogues he's mind-controlling.
The Time Trapper served as this during Paul Levitz's v3 run in the 1980s.
Black Guy Dies First: The post-Zero Hour Legion's roster as of their first mission included four white guys, three white girls (or five, depending on how you count Triad), a black guy, a black girl, an orange guy, and a green guy. Guess who died the first time out. If you guessed the insufferable jerk with the technology-based powers who also happened to be the only black guy, you win a first-class ticket to the funeral of James Cullen (Kid Quantum I).
Brain in a Jar: The Brain Globes of Rambat. Started out as villains, but in the Post-Zero Hour continuity, they were just another member of the United Planets.
Break the Cutie: v4 did this with a number of characters, but particularly harshly with the White Witch. Previously depicted as a slightly shy, bookish type in a (platonic?) relationship with teammate Blok. At the start of v4, she was shown to be in an abusive marriage with former archnemesis Mordru. She was rescued by the reconstituted Legion just in time to discover that Blok had been brutally mutilated by genocidal pirate Roxxas the Butcher.
Broken Angel: Dawnstar in v4 lost her wings after being possessed for three years by Bounty, a thrill-seeking entity that used her tracking powers to go into business as a bounty hunter. The reason for this was never explained.
The Legion logo, a stylized letter "L", shows up as a shared motif on many Legionnaire costumes (usually as part of the belt buckle), and is part of the design of the standard flight ring.
Element Lad's original costume had a big "E" on it. He still wears an "E", only the Interlac version, which looks like a sideways "J".
Cain and Abel: Lightning Lord versus his younger brother Lightning Lad (and to a lesser degree his sister Lightning Lass).
Captain Ersatz: Mon-El (a Captain Ersatz of Superboy) and Andromeda (a Captain Ersatz of Supergirl), after both Superboy and Supergirl were RetConned out of existence by The Man of Steelreboot by John Byrne. Byrne has since admitted that removing Superboy was a mistake. Note that Mon-El was a separate character before the Retcon. They had to bend over backwards in order to re-position him as a Superboy stand-in (whereas Andromeda was a straight Suspiciously Similar Substitute).
Cast Speciation: "All Legionnaires must have at least one unique power" used to be a rule, though it was introduced much later than commonly thought. The Reboot version merely "encouraged a diversity in powers", because by the time they got to write their own constitution they already had the matching powers of Live Wire/Spark and M'onel/Andromeda/Ultra Boy, none of whom they wanted to force out. (Side note: Ultra Boy still qualified as having a unique power, in addition to being invulnerable to both kryptonite AND lead. His penetra-vision could see through lead, which the others could not.)
Characterisation Marches On: When she first appeared as an Amazer, Monstress talked like Ben Grimm and snarled "I'm Monstress, an' that's my only name!" When she became a Legionnaire, it turned out her real name was Candi Pyponte-Le Parc III, and her personality was very much what you'd expect from someone called Candi Pyponte-Le Parc III, darling!
V4 featured a lot of this, although how much of it was really evolving characterisation and how much was an outright retcon is up for debate. Notable examples include the SW6 versions of Lightning Lad (later Live Wire) and Sun Boy (later Inferno), both of whom had traditionally been depicted as responsible, team-oriented guys, and were now being written as brash, impulsive, and irresponsible hotheads.
Chest Insignia: Lots of them, starting with Saturn Girl (although the symbol was changed to a mandatory telepath ID in the post-Zero Hour version) and Lightning Lad. Even the members who don't wear one get a symbol by which they're represented on things like rosters, mission team lists, status listings, and so on.
Chekhov's Gun: Lots and lots. Particularly in the Legion of 3 Worlds
Without his ERG-suit, Wildfire is just a mass of anti-energy, shapeless and largely unable to interact with the rest of the world.
Quislet required his "costume" (actually a miniature spaceship) to survive in our dimension. When it was destroyed, he had to quit the team.
Cloning Blues: Batch SW6. They're not clones. Maybe they are. Never resolved.
It was resolved, but not necessarily to anyone's satisfaction. Apparently, as originally created by TMK, they were intended to be the original team, with the adults actually being the Dominators-created clones. The editors refused to let them run that storyline, though, and the canonical explanation was given later during the "End of an Era" storyline leading up to Zero Hour: they're not clones, they're the originals from a forked pocket dimension created by the Time Trapper during one of his attempts to protect the team from being caught up the universal destruction he knew was going to occur. That the Dominators found them in stasis and stored them under 30th century Metropolis was, apparently, just a coincidence.
Cosmic Retcon: A lot. Most of the time, major changes to LSH continuity are explained on panel.
The first such example was the brief "Mordruverse" story arc early on in the Giffen/Bierbaum run: Mon-El kills the Time Trapper, eliminating his influence on the timeline and erasing the Legion from existence. In the apocalyptic Crapsack World that results, the universe is ruled by evil sorcerer Mordru, and Glorith, one of his brides, strikes a deal with the resistance and agrees to be sacrificed to take the place of the Time Trapper and the universe is restored... with some key differences.
The post-Zero Hour reboot gets similar treatment. At the tail end of the 5YL run, leading up to the company-wide Zero Hour crossover event, random characters who were believed to be dead (or never existed in the first place) start popping into existence (like SW6 versions of Star Boy and Dream Girl). Meanwhile, in light of the chaos, Legion archfoes Mordru and Glorith bury their rivalry and team up, kill and absorb the universe-shaping power of another old time Legion enemy, the Infinite Man, and set about remaking the universe in their image. In the process, they kidnap LSH cofounder Cosmic Boy and trapping him in the Infinite Library. Trapped therein, he spends several lifetimes reading and memorizing the books therein. Armed with the knowledge of how time itself is fraying, and the ability to try and do something about it, he escapes the library and sets out to try and save his team from their impending doom. Unfortunately, his every attempt makes matters worse, and ultimately, as he put it, "I fear I went slightly mad." Forgetting his mission, even his original identity, he dons a stylish purple robe and hood and becomes the Legion's greatest foe, the Time Trapper. He snaps back to sanity after encountering his past self, and teams up with the Legion to defeat Mordru and Glorith. Unfortunately, the Trapper's past manipulations remain a festering wound in the timeline, and the only way to repair time is for the Legion to sacrifice themselves and allow time to be rewritten without the influence of the Trapper or others of his ilk, leading to the reboot Legion.
In keeping with tradition, the rebooted Legion is given a similar storyline to end their run and bring in the "threeboot." Fatal Five member Persuader discovers he can use his Atomic Axe to slice through realities into parallel universe, an ability he uses to recruit 100 other versions of the Fatal Five to go against his Legion. The combined forces of the Legion and the time-traveling Teen Titans defeat them, but in doing so destroy every Atomic Axe. The resulting release of energy strands the Legion in the time stream, and slices off their original universe from the mainstream DC universe, replacing it with the threeboot world.
A number of individual planets were presented that way. Examples include Rimbor, a hub for organized crime, and Durla, a barren, insular, and xenophobic world.
Most of the galaxy during the "Five Years Later"/v4 continuity, with a particular emphasis on earth.
And even earth, for all of its problems, seems preferable to the brief glimpse we had of the universe in the fifth issue of that run: all technology, and superheroes, were outlawed, and much of the galaxy was ruled with an iron fist by Mordru.
Try being a teen in the "Threeboot" universe. It's what ignited the Legion's spark.
Curb-Stomp Battle: Happened to the Legion more than you'd think, given the number of extreme powerhouses on the team. It was fairly common whenever they went up against the Time Trapper, Mordru, or Glorith.
Cute Mute: Saturn Girl. While the original version of the character and the rebooted version are just young girls who happen to have awesome telepatic powers, Threeboot Saturn Girl happens to be a mute girl, hailing from an entire planet of mute individuals, needing her telepathy to be able to communicate effectively.
Cypher Language: Interlac. Many of the invented characters even look suspiciously like their Latin counterparts.
Darker and Edgier: The "Five Years Later" continuity in the comics; the Abnett and Lanning run of the post-Zero Hour reboot, particularly "Legion of the Damned" (which still had a happy ending) and "Legion Lost"; the second season of the cartoon.
Dark Age of Supernames: After being a famous example of Something Person names during The Silver Age of Comic Books, the trended started to shift during The Bronze Age of Comic Books in the mid-1970s, with new characters like Wildfire, Dawnstar, Tyroc, Tellus, Quislet, and Atmos. The pace picked up considerably during the TMK run starting in 1989, with Valor, Impulse, Bounty, Kono, Veilmist, Firefist, Flederweb, and Nightwind. But it reached its pinnacle with the introduction of SW6 teenage duplicates of the team, many of whom adopted "edgier" versions of their original names (see below for examples). Most of these names were kept for the post-Zero Hour reboot, and new characters introduced during this period usually started off with such names (Catspaw, Dragonmage, XS, Kinetix, Gates, Thunder, Monstress). When Mark Waid started writing the "threeboot" version of the team, he deliberately returned to the traditional Something Person convention, and the post-Final Crisis version of the team has stuck with it as well, though not as zealously.
Chameleon Boy → Chameleon
Colossal Boy → Leviathan
Element Lad → Alchemist
Used for the SW6, but switched back for the reboot.
Death Is Cheap: Despite being somewhat famous for averting this trope more often than not, the eventual return of the first ever Legionnaire to die (Lightning Lad) was telegraphed before his corpse was even cold.
Demoted to Extra: Tons of Legionaires have suffered this, most notably Wildfire and Dawnstar, who were amongst the most popular characters of the original Legion.
Disability Superpower: Ferro Lad and his twin brother. Born with horrible deformities that left their faces scarred and mutilated and forced them both to wear full-face masks. Their consolation was the ability to transform into "living iron." Also the White Witch, born on a planet of precognitive seers but without that ability herself. She did, however, show an innate talent for magic and eventually became one of the most powerful sorceresses in the galaxy.
Doppelgänger Spin (or Attack): Triplicate Girl/Triad/Duo Damsel. Trijitsu is a Carggite martial art involving splitting and recombining strategically in combat.
Driven to Villainy: The Time Trapper (a.k.a. Cosmic Boy) in his v4 origin story. The Progenitor (a.k.a. Element Lad) in the original Legion Lost.
Dropped a Bridge on Him: A specialty of the Bierbaums, who dropped a number of bridges on Legion members they hated.
Timber Wolf was mutated into a mute, inhuman beast that was treated like a pet by his teammates.
Wildfire was killed off in the Noodle Incident known as Black Dawn, with the only details stated being that his death was horribly violent.
Shvaughn Erin was turned into a pathetic stalker/transsexual who was addicted to gender-bending drugs. Sun Boy turned traitor and ended up being horribly burnt, to the point that he was mistaken as a monster by his own friends.
Writer/artist (and Legion superfan) Colleen Doran was overheard at a con referring to Shvaughn Erin as "Sean" many months before the Bierbaums worked their strange magic on him/her.
The first Legion Lost series did this to Monstress, one of the non-legacy characters, at the climax. The second Legion Lost series did this to Chameleon Girl and fan-favorite Gates (the only character on the team not created before 1990) in its first issue, mostly just to show how "serious" the title was.
In general the Threeboot Legion got this treatment in "Legion of Three Worlds" where they had more members of their Legion dying and basically being swept under the rug to make the old Legion the main Legion.
Due to the Dead: Legionnaires killed in battle are buried with honors on Shanghalla, an asteroid used for this purpose by a number of civilizations of different races. Messing with Legion corpses is a great way to commit suicide-by-angry-superheroes.
Elemental Embodiment: Both the Infinite Man and the Time Trapper were, at one point, described as the living embodiment of time itself. However, they both represented different understandings of the nature of time: the Infinite Man represented an open, infinitely repeating universe, while the Time Trapper represented decay and entropy. As you might expect, their meetings were explosive.
Elemental Shapeshifter: Stone Boy is a Substitute Legionnaire who can turn into an immobile statue. However, he manages to use this power effectively anyway.
The Fatal Five were originally introduced as such, as the Legion was shorthanded and needed help to defeat the Sun-Eater. The only help available happened to be the five most-wanted criminals in the galaxy.
Played with quite a bit during the v4 run, as the Legion would temporarily strike a truce with one of the three evil Powers That Be (the Time Trapper, Glorith, or Mordru) to counterbalance the other.
Engineered Public Confession: Cosmic Boy tricks corrupt United Planets President Chu into listing all of her crimes on live television (or the closest 30th century equivalent, at least).
Everyone Is a Super: A lot of planets in the Legion universe are like this: Titan (everyone is a telepath), Naltor (where everyone has precognitive visions), Durla (a planet of shapeshifters), and Braal (magnetism).
Two of the three original members of the Legion of Super-Villains definitely qualify. Saturn Queen's telepathic powers are similar (though not identical to) Saturn Girl's powers, and Lightning Lord is Cain to Lightning Lad's Abel. It's actually partially averted with Cosmic King, though: despite a similar name and a knock-off costume, his powers (transmutation of elements) have very little to do with Cosmic Boy's super-magnetism.
The Chick and The Big Guy — Played with. Night Girl is the literal chick, but her powers make her the team's powerhouse. Stone Boy's rock powers make him a more traditional big guy, but his lack of confidence mixed with a great caring for others puts him in the chick slot.
Which is probably why the writers broke away from following that timeline, which then required a parallel universe story to explain it away.
Flying Brick: Superboy, Supergirl, Ultra Boy (but only one power at a time), Mon-el/Valor (without kryptonite-phobia to harsh his cool), and Andromeda.
Fountain of Youth: The Time Trapper's first appearance involved this shtick, when he returned the Legionnaires to infancy. Later affected a number of Legionnaires for a longer period following an ill-conceived attack on Glorith late in pre-Zero Hour v4: Shrinking Violet catches Merlin Sickness from the experience, while the White Witch is merely deaged to sixteen. Brainiac 5, meanwhile, gets stuck with an Overnight Age-Up.
In both the original and postboot continuities, the White Witch was "the Hag," a wizened old crone, as a result of Mordru's curse. She got better (and younger).
Frameup: Happened more than once, but most notably during the tail end of pre-Zero Hour V4. The Legion is accused of aiding perennial bad guy alien race the Khunds by Heel Face Mole Universo. Hunted by the authorities, the team adopts a new set of heroic identities and sets out to clear their (original) names.
Fugitive Arc: In an old story, the Legion is outlawed following an evil scheme by Universo to take over the government of Earth. With the mightiest members of the Legion having been shipped off to a prison planet, the others of the Legion have to stay one step ahead of the law while trying to break their buddies out and get to the bottom of the whole mess.
Future Me Scares Me: Cosmic Boy's reaction to meeting his future self (the Time Trapper) in the "End of an Era" closing out the 5YL run.
A much milder example in the form of the threeboot Brainiac 5, who finds difficulty in working with his (adult) retroboot alter ego.
Future Slang: "Grife" (interjection), "sprock" (verb), "nass" (noun, generally referring to an object or idea), and "squaj" (noun, generally referring to a person) are some of the more memorable terms, probably because they're all swear words. "Unlax" (relax), "persp" (perspire/ act nervous), and others also exist in more child-safe usage.
Notably, there were at least two canonical methods of gender bending defined in the series. The first, a disease with temporary effects, was usually played for comedic effect (often involving the Legion of Substitute Heroes or Matter-Eater Lad), and the second (used for the Shvaughn/Sean Erin story arc) was induced by drugs.
Colossal Boy, the Legionnaire known for having a big heart no matter what his size.
Blok, who was a soft-spoken and solitary rock creature.
Also Monstress from the post-ZH Legion.
Genius Bruiser: Blok, a giant rock-creature and the Legion's archivist.
God Guise: Valor (Mon-El) was worshiped by most of the galaxy in the post-boot continuity for founding most of the Planets of Hats the Legionnaires came from back in the twentieth century. In order to avoid getting crazy reactions wherever he went, he changed his costume slightly and took the codename M'onel.
"The End of an Era", the storyline that concluded the pre-Zero Hour run. The Legion and their SW6 dopplegangers face off against both Mordru and Glorith as the universe is being erased around them. They win, but are forced to sacrifice their lives in order that their entire history may be erased and "done over" without the influence of Mordru, Glorith, and the Time Trapper. The series continues, but with a total Continuity Reboot, effectively shutting the door on three and a half decades of Legion storytelling.
The post-Zero Hour Legion comes to a similar conclusion with the Teen Titans / The Legion Special, which destroys the team's entire universe. The Legionnaires survive (for the most part), but everything else introduced during that run is destroyed, and the team reduced to occasional guest shots in other books as the new Wanderers.
The Greatest Story Never Told: All of the Legion of Substitute Heroes' silver age adventures ended with the Substitute Heroes having a magnificent adventure that nobody would ever learn of.
Great Offscreen War: The Braal-Imsk conflict during the five-year gap preceding the Giffen/Bierbaum run is only seen in flashback glimpses, but it casts a massive shadow over subsequent events. Black Dawn may also qualify, but since it's also a Noodle Incident, it's hard to say for sure.
Lightning Lad/Live Wire and Lightning Lass/Light Lass/Spark, to varying degrees.
The entire planet of Winath where they were born was full of examples of this trope. Twins were the norm rather than the exception (by something like 99-to-1 percent), and while some pairs were single-gender, there were plenty of counter-examples as well.
Heel Face Door Slam: During v4's "Terra Mosaic" story, Earthgov president Tayla Wellington, who up to that point had been a Puppet King put in place by the Dominators, attempted to make a plea on live holovid feed that Earth desperately needed help and had needed help for years before she was shot in the head by a Dominion agent, while still on air. If anything though, the footage of her death was what prompted the United Planets to finally make a move against the Dominion's hold on Earth.
During that same story, Sun Boy finally attempted to do some good after being a willing puppet of the Dominion for the sake of fame and fortune, only to be violently rejected by Earth's masses for being a traitor. To make matters worse, Dirk was caught in a nuclear blast that transformed him into a walking corpse that is constantly aflame.
Heel-Face Revolving Door: A lot of debatable examples of this because of the frequent Continuity Reboots the team has been through. Many of the Heel Face Turns during the Giffen/Bierbaum run (Lightning Lord, Saturn Queen, Spider Girl, etc.) were subsequently invalidated when that entire run was consigned to the dust bin. But Mordru is an example of this within a single continuity: he was cured of his megalomania towards the end of Paul Levitz's v3 run, and was even married to the White Witch in during the five-year gap between v3 and v4. By the start of v4, he was back to his old tricks again.
Heel Face Mole: Preboot, Universo was a disgraced Green Lantern (he went through an offscreen Face-Heel Turn) and skilled hypnotist who had crossed paths with the Legion a number of times. During the five year gap between V3 and V4, he seemingly reformed and became a high-ranking figure in the Earth resistance movement. As a result, when the Earth is finally liberated, he becomes a high-ranking figure in the new Earthgov... a position he uses to frame the Legion as collaborators with the warlike Khund race and have them temporarily outlawed, forcing the Legionnaires to adopt disguises and go on the lam.
Surprisingly, Earth Man (of all people) in the latest series
Blok started off as a member of a team of villains seeking revenge against the Legion for the destruction of his planet. Turns the Legion wasn't responsible and were actually trying to evacuate the survivors, so he switched sides.
Infectious Lass from the Legion of Substitute Heroes, as well.
Heroic BSOD: The White Witch near the beginning of v4, following being rescued from her abusive marriage and seeing her previous love interest Blok get butchered.
Heroic Sacrifice: Practically a Legion tradition. Notable examples include Ferro Lad, Karate Kid, and Magnetic Kid, among many others.
HeroicSociopath: Shrinking Violet/Atom Girl in the Threeboot Legion, subverting the personalities of her previous incarnations.
Hide Your Lesbians: Very weakly attempted during V4 with the relationship between Lightning Lass and Shrinking Violet. In truth, the only real difference between this particular relationship and any of the heterosexual relationships being depicted in the book was that the writers generally avoided referring to the two as lovers: the innuendo was both intentional and obvious, and the masquerade was put on solely to appease the editorial guidelines of the day. Lightning Lass and Shrinking Violet have thankfully been confirmed to be a couple in the current series and they are both adorable and kick ass together.
Threeboot Star Boy, as a black gu—excuse us, Xanthuan, can't eat sugar, and Reboot Ultra Boy, as a Rimborian, has a set of organs which don't correspond to the human body at all.
In the first Post-Crisis continuity, this was Retconned so that all of the Human Aliens were actually humans who were sent to colonize other planets after gaining superpowers during Invasion... and Projectra, still an actual alien, was a snake.
Humans Are White: There have been comparatively few dark-skinned Legionnaires. This ties into Executive Meddling in the original continuity. Jim Shooter originally intended for Ferro Lad to be black, however Mort Weisinger vetoed the idea afraid that DC would face backlash in the South. Unhappy that he was unable to do what he originally intended with the character, Shooter decided to write out the character with his now legendary Heroic Sacrifice. The Legion wouldn't get it's first black member until Tyroc in 1976... which was also a sore spot with creators. Shooter was unhappy that Tyroc was a black character instead of a character who happened to be black. Mike Grell intentionally gave Tyroc the worst design he could think of as protest. Tyroc was so unpopular with Legion creative teams that he was the only Legionnaire introduced before Paul Levitz's decade-long run on the title that was never used. Levitz put him on a bus and never referred to him. He did finally use the character when he returned to the title in the 2010s, though.
Joker Jury: "The Devil's Jury" in Action Comics #370.
Kick the Dog: Akka is Saturn Queen's most loyal ally throughout the Legion of Supervillains story arc in the current series. How does Saturn Queen reward her? She stabs her in the chest
Kudzu Plot: Suffered from this big-time in v4, partially due to Executive Meddling. Within the first dozen issues, the list of plot threads was already a mile long: the reestablishment of the team, filling in the off-screen backstory from the five year gap preceding the series launch, liberating Earth from its alien oppressors, explaining the presence the SW6 duplicates, numerous "where are they now?" side stories, and so on. By the end of the run the writers had only worked their way through about half of these, resulting in a final story arc that was mostly Infodump and which still left a number of dangling threads.
Kryptonite Factor: For Superboy and Supergirl, Kryptonite itself. Mon-El/Valor/M'Onel and Laurel Gand/Andromeda were similarly affected by lead (though a cure for lead poisoning was later introduced). Ultra Boy suffered from a critical limitation in that he had the same suite of powers of Superboy or Mon-El, but could only use one at a time: he could be super-strong, but not invulnerable at the same time.
On the villain side of things, Mordru had a phobia of being buried alive that was so great that it reduced to him to near-catatonia and rendered him helpless.
Lady Macbeth: Charma's powers were to make men do whatever she wanted, and to make women hate her to the point of physical violence. She wound up imprisoned by her school's headmistress when she was nearing graduation, escaping by working her charms on her jailer, Grimbor, who embarked on a criminal career of his own, first by her side, and later solo.
Last of His Kind: Superboy was originally the last Kryptonian, but that was quickly abolished when Supergirl joined up. Then restored with "Crisis on Infinite Earths." Then erased again with "Supergirl & the LSH." Meanwhile, Legionnaires Blok and Element Lad really are the last of their kinds; E-Lad's homeworld, Trom, was depopulated by Roxxas & company, and Blok's world of Dryad was destroyed by the Dark Man.
Late Arrival Spoiler: Sensor Girl is really Projectra. Note that this only recently returned to being a Late Arrival Spoiler because the book is back to using the original Legion.
Lawful Stupid: In the early stories the Legion could fall into this way too often. In one instance Supergirl was not accepted into the Legion despite passing her iniation test with flying colours because she had been temporarily aged to an adult after accidental exposure to Red Kryptonite and thus was barred from membership due to being over 18. Aside from the fact the aging was temporary the Legionnaires knew she was really only 15 years old but still disqualified her.
Brainiac 5, introduced as the great-great-grandson of Superman villain Brainiac, was so popular that writers eventually created Brainiacs 2, 3, 4, 6, 8, 12, and 13.
Jenni "XS" Ognats, granddaughter of Barry "The Flash" Allen and cousin of Bart "Impulse" Allen.
Thom "Star Boy" Kallor has been revealed to be a part of the "Starman" legacy, as well, which James Robinson had set up during his Starman run.
The post-Zero Hour Legion had a legacy entirely within the future timeline, with Kid Quantum I being killed on the first mission and his sister taking up the name- first as a member of home-planet team The Uncanny Amazers, and eventually as a Legionnaire.
Not just the team, but the Legion titles seem to exist in a universe all their own. In the 1980s, DC released a Who's Who maxi-series dedicated solely to the Legion, covering just about every named character that has been in a Legion-related book since the 1960s.
In Valentino's normalman, the legion was parodied as "The Legion of Superfluous Heroes". Their roll call was so long it had to be spread across ten issues.
And even with a membership in the gazillions, the Legion of Super-Heroes has enrollment standards. Some of those who didn't make the cut formed their own Legion of Substitute Heroes, thus giving us even more characters.
Lost Episode: Sort of. A very significant story (the wedding of Saturn Girl and Lightning Lad) was originally published as an oversized, tabloid-sized special in the mid-1970s. It was never truly lost, but because of its unusual publication format (especially in the days before eBay) it remained extremely hard to find in the usual places where a fan would look for such things (specialty comic book store back issue collections, mainly). Gained the nickname "That Damned Tabloid" in fandom as a result. It was eventually reprinted as part of DC's hardcover archive collection in the late 1990s.
In the original canon, R.J. Brande is Chameleon Boy's father.
Postboot, the leader of the Dark Circle is really Brainiac 5's mother, Brainiac 4.
MacGuffin: The mysterious canister stolen from Earthgov during TMK's run served as the catalyst for Spider Girl/Wave's Heel-Face Turn and played a role in the liberation of Earth from the Dominators. It was probably intended as part of some aborted storyline, but it gets pushed to the sidelines by the time Wave has formally joined the Legion, and is not mentioned again.
Merlin Sickness: Shrinking Violet is literally afflicted with this following an ill-conceived attack on Glorith towards the end of the pre-Zero Hour v4 run.
Mind-Control Device: Recurring villain Universo went through a procession of these, allowing him to amplify his natural talents for hypnosis over larger and larger scales, be it an entire planet or much of the galaxy. One of these, the Hypno-Stone of Titan, was also involved in a subplot involving Matter-Eater Lad and reformed villain Saturn Queen during the Giffen/Bierbaum run.
None of them hold a candle to the Time Trapper, which is finally explained in Legion of Three Worlds: According to Brianiac 5, the Time Trapper is a sentient timeline who is rebelling against the Legion's timeline.
Nice Job Breaking It, Hero: Cosmic Boy's (or, rather, the Time Trapper's) attempts to protect the Legion using the abilities learned from the Infinite Library in "End of an Era" only make the already-bad situation worse.
Noodle Incident: Black Dawn. Though later writers attempted to tell the story (with various success), none really line up with the details given by TMK.
The only details we know for sure is that it involved the sun almost going out, Wildfire apparently died (he survived, but floated around the galaxy as a disembodied consciousness for a few years), and Timber Wolf was hit with a blast of radiation so bad it mutated him into Furball.
Only Known by Their Nickname: A few Legionnaires are addressed almost exclusively by their codename or derivations thereof, notably Shrinking Violet (Violet, or Vi), Brainiac 5 (Brainy), Chameleon Boy (Cham), and Gates.
Initially, in keeping with the mood of the Silver Age, this applied to everyone. Later on, it was much more common to hear team members refer to each other with their real names, save for the previously mentioned exceptions.
The Plan: Cosmic Boy in the post-Zero Hour reboot continuity employed them often; Brainiac 5 in the current comics continuity seems fond of them, too.
Planet of Hats: The "hats" in this case being the superhuman powers shared by all or almost all of the inhabitants of various planets, though the trope also applies in the traditional sense: Winath is the farming planet, Rimbor is the slum planet, Colu is the computer planet, etc.
Powered Armor: Wildfire's suit. Brainiac 5 briefly wore something like this after being aged by Glorith.
Power Trio: Cosmic Boy, Lightning Lad/Live Wire, and Saturn Girl, in the comics.
Leland McCauley in the Postboot continuity (who was actually Batman's immortal foe Ra's al-Ghul in disguise at the time). He was still definitely evil in the Preboot and earlier in the Reboot continuities, but was a Corrupt Corporate Executive, not president (and wasn't Ra's, either).
Universo has been president of Earth a time or two as well, inevitably creating a fascist state immediately thereafter with his mind control abilities.
Earthgov presidents Tayla Wellington and her successor Arlington Morse from the "Terra Mosaic" story arc in v4 are this, as well (both of whom were Puppet King for the Dominators)
As was United Planets president Jeanette Chu earlier on in the Postboot continuity. Possibly an overused trope, all things considered.
Princess Incognito: Projectra, during her Sensor Girl phase. Originally her identity was obscured even from her teammates, but it remained a public secret for even longer.
Prophecy Twist: Pretty much any significant prophecy provided by Dream Girl/Dreamer's powers tends to be subject to this.
Psychic Powers: Saturn Girl, Dream Girl, Tellus, among others... including everyone on those characters' respective home planets.
Psycho Electro: Lightning Lord. In the post-Zero Hour Legion, Live Wire (Lightning Lad) was afraid that the powers he and his siblings gained drove his brother mad, and that he and his sister would be next... until he finally saw his brother again and realized that blaming it on the lightning would excuse Mekt's generally being a sociopathic Jerk Ass who killed people on a whim.
Punny Name: Ultra Boy's real name, Jo Nah. He got his powers after being devoured by a space whale.
Puppet King: During the "Terra Mosaic" story, in which Earthgov had been secretly taken over by the Dominators, President Tayla Wellington was a textbook example of this. After a failed Heel-Face Turn, that role is taken over by her vice-president, Arlington Morse.
Put on a Bus: Tyroc for the duration of Paul Levitz's run as writer during the 1980s.
Red Skies Crossover: Legion of Three Worlds was billed as a Final Crisis crossover and had the cover logo, but had no real connection to Final Crisis.
Reed Richards Is Useless: Despite all of the big brains on the Legion roster, none of them want to or can be bothered to try and help restore Wildfire to some semblance of humanity. It was Quislet of all people to be the one who restored Drake to human form!
Jim Shooter began submitting stories and layouts to DC in 1966 at the age of thirteen, after following the series as a fan. He returned to begin writing for the Threeboot incarnation of the Legion at the end of 2007.
The TMK run was infamous for sounding like overwrought fanfic elevated to canon. Because it was, in a manner of speaking (though whether or not it was actually overwrought depends on the observer): Tom and Mary Bierbaum (the "TM" in "TMK") were active participants in the Legion of Super-Heroes APA scene in the 1980s, and many of the ideas they introduced when they were writing the title were originally conceived in those pages.
Sacrificial Lamb: The first Kid Quantum was created just to be killed to illustrate the need for the Legion's "no external powers" rule.
Sacrificial Planet: The origin story of minor villain Mano features him using his disintegrator power to destroy his entire homeworld and everyone on it. Given that he was never even remotely that powerful in any of his actual appearances, it almost reads as an example of Cutscene Power to the Max.
San Dimas Time: Particularly when half the Legion got stranded in the 20th Century during the post-Zero Hour continuity.
Scandalgate: The crisis of the United Planets' Portal Network being subverted by an alien power and used to invade Earth is referred to as "Softgate."
Scars Are Forever: Shrinking Violet is scarred during the five-year gap period between v3 and v4 and keeps the wound until the Zero Hour-induced reboot. 30th century medicine is more than capable of repairing the damage, but since she earned it during an unjust war with her former teammate's planet, she takes it as her My God, What Have I Done? moment and continues to wear it as a protest.
Secret Identity: Averted, unlike most superhero comics. The identities of all members are known to the public... except for Sensor Girl in the original continuity, whose identity isn't even known to the Legion for a while, and M'onel in the Zero Hour reboot, who won't let anyone find out he's the mythical Valor who first seeded their worlds with life because it'd be impossible to have a life of his own afterward.
Secret Test of Character: The first story with them involved an "initiation" for Superboy which was three separate Secret Tests. This story was later repeated with Supergirl.
Reboot Cosmic Boy attempts a mild version of this on Superboy v2 in the Teen Titans/The Legion Special, asking him to choose between saving his original team (the Titans) or his new team (the Legion). Superboy doesn't fall for it, and Cosmic Boy sheepishly responds that he couldn't resist: "it's a Legion thing."
Self-Sacrifice Scheme: Saturn Girl devises one of these to resurrect Lightning Lad. Several Legionnaires agree to stand around the latter's casket, holding lightning rods. One of them will be struck by lightning, the result of which would be to revive Lightning Lad at the cost of the hero's life. Unbeknownst to everyone else, though, Saturn Girl has sabotaged all but her own rod... except that it doesn't quite work as planned (see the entry for "Taking the Bullet" below).
It's not like the Legion didn't have plenty of questionably attired heroes, but even when this was common during Mike Grell's run as artist, it wasn't unusual to see the villains wearing even less than the heroes, as was the case with Grimbor the Chainsman and his partner Charma, who were dressed as a bondage duo.
In the postboot era, this was typified during the "Emerald Legion" story, where the Emerald Eye-possessed Legionnaires all get much skimpier (and greener) costumes.
Shape Shifting Squick: In fact, in the threeboot, someone suggests that Chameleon is not attracted to non-shapeshifters. Averted in the original continuity, though, where Colossal Boy and Chameleon Girl (a different character) have a happy marriage.
Shell-Shocked Veteran: Shrinking Violet in v4 continuity. Arguably averted in the case of Cosmic Boy in the same period: he was physically scarred and lost the use of his powers, but remained The Heart that he always was.
Silly Rabbit, Idealism Is for Kids!: Following the return of the original Legion in Action Comics and Legion of 3 Worlds, the various dignitaries of both Earth and the United Planets have become convinced that the Legion is nothing more than a child's fantasy of peace and cooperation with no chances of happening, now that Earth has "shown its true colors" thanks to Earth-Man's Justice League of Earth. The Earth President supports the disbandment because he's a xenophobe, and the United Planets supports it because of all the damage Earth has done to its alien citizens. The U.P. even point out how "naive" the Legion is by mentioning that, even though most of the members are adults, they still refer to themselves with "boy, girl, lass, and lad" in their codenames.
Sleepwalking: For most of his career, Substitute Legionnaire Stone Boy was limited in that his ability to turn to stone worked as a form of hibernation. During the five-year gap period, he Took a Level in Badass with his fellow Subs, and was trained to sleepwalk, rendering him substantially more threatening to his enemies.
Something Person: Ridiculously common in early Legion names; played down post-Zero Hour, but intentionally preserved in current continuity. It was deliberately played up in threeboot continuity, in one case even changing a pre-Dark Age of Supernames character (Shrinking Violet) to fit (Atom Girl).
Space Pirates: Roxxas, the Sklarian Raiders, and undoubtedly others.
The Legion is a spin-off of Superboy (who is himself a spin-off of Superman). Members Cosmic Boy, Timber Wolf, Karate Kid, and Mon-El have all had Spin-Off series of their own, as have the Legion's fellow future Super Team, the Wanderers, and Sixth Ranger Inferno.
L.E.G.I.O.N. (later R.E.B.E.L.S.) is a slightly unusual example: it's a Suspiciously Similar Substitute for the Legion, with similar characters and a similar space-operatic style, but set in the contemporary 20th/21st century DCU.
Spinoff Babies: The SW6 clone team, who starred in pre-Zero Hour Legionnaires.
Strawman Political: Gates from the Post-Zero Hour Legion. But he's a rather unusual case, since the writers consistently treated him as a three-dimensional, sympathetic character despite his often silly beliefs, rather than a convenient political target to knock down.
Suicide by Cop: Darkseid during "The Quiet Darkness." A brilliant scientist saves his dying wife during her pregnancy by striking a deal with Darkseid in exchange for implanting the unborn children with the "Gemini Matrix" to raise them to a more powerful plane of existence. Darkseid then takes over the planet in order to prevent the children from fleeing, and finally goads the twins into attacking and killing him. His final words suggest that this was his plan all along: a god like Darkseid was only capable of being killed by another god. Since there weren't any available, he had to create his own, and make them hate him enough to kill him.
Super Dickery: The Legion were made of this in their early appearances. Most early Legion stories consist of the Legionnaires being jerks to each other, only to reveal at the last minute that it was for the greater good. Arguably, the most famous example is a story in which Saturn Girl mind-controlled the Legion into electing her leader and then stole all of their powers so that she could ensure that she would be the Legionnaire to make a prophesied Heroic Sacrifice.
Time Master: The Time Trapper, the Infinite Man, and Glorith, on the villainous side. For the heroes, there's Kid Quantum, though at a greatly reduced level.
Time Travel: Originally it was all over the place, as the means by which Superboy could be a member of a thirtieth-century superteam. After the Zero Hour reboot, it's extremely rare, and half the Legion being sent a thousand years into the past (where they can interact with most of the rest of The DCU) poses a huge problem in terms of how to get them home.
Took a Level in Badass: After spending much of their history as running jokes, the remaining members of the original Legion of Substitute Heroes did this during the five year gap leading up to the v4 series. With the original Legion discredited and disbanded, they became the leaders of the resistance against Earthgov's abuses. Ironically, Polar Boy, the only former member of the team to have actually graduated to the majors on panel, was shown in a rather negative light, having failed to prevent his team from dissolving and then getting arrested for attempting to incite a riot.
Too Many Belts: When Keith Giffen returned to the title as artist in the late 1980s, he brought with him a radically changed art style and a complete redesign of the costumes of the team. Those redesigns eschewed the traditional spandex superhero aesthetic in favor of jackets, belts, and pouches. Lots and lots of pouches. And this was beforeRob Liefeld hit the big time...
Twenty Minutes into the Future: Until some point in the 1960's, The Legion's era was said to be not 1000 years but only 100 years ahead. Writers moved it all up when it dawned on them that this type of galactic community would be more than a century in coming around. Oddly enough, the 1000 year difference came first, being mentioned in the first few Legion appearances. After that, the writers switched to 100 years with no explanation, which stuck for a few years before switching back to 1000.
Twin Threesome Fantasy: Bouncing Boy married Duo Damsel when they left the team to run the Legion Academy. He wears two wedding rings and assures Wildfire that "being married to a woman who can become TWO people" is quite an experience.
Unfortunate Item Swap: Bouncing Boy owes his superpowers to this - he mistook a bottle of experimental Super Serum (which he was supposed to be delivering when he got distracted) for the bottle of soda pop he'd just bought.
Wham Episode: Almost any story featuring the Time Trapper during the 1980s and early 1990s could be considered an example of this. Especially the "Mordruverse" two-parter near the beginning, and "End of an Era" at the end of v4, pre-Zero Hour. Also, Secrets of the Legion of Super-Heroes (R.J. Brande is really Chameleon Boy's father), v3 annual #2 (long-time villain Validus is really the child of Lightning Lad and Saturn Girl), and the conclusion of Cosmic Boy's plan against President Chu in the post-ZH book.
Wham Line: At the end of the final New Fifty Two issue, Bouncing Boy mentions Superman being killed by Steppenwolf, implying that this takes place in the 30th centuty of Earth 2.
A token effort was made to resolve a number of threads during "The End of an Era" storyline wrapping up pre-Zero Hero v4, but several more fell through the cracks, including the revelation of what was in the canister Spider Girl stole and that most of the galaxy was willing to kill her over (see the entry on Aborted Arc above).
At the end of the Postboot era, plot points that were left unresolved included Apparition's missing sister, Apparition and Ultra Boy's rapidly aging son, the disappearance of Computo and the mysterious figure who "stole" him (probably the Time Trapper), the apparent rebirth of Darkseid, Ra's al-Ghul staying in custody on Legion World, the romance between Cosmic Boy and Kid Quantum, and a hinted-at subplot in which the Time Trapper would have turned out to be Cosmic Boy and XS' son....
In regards to the Threeboot Legion there's the matter of Princess Projectra's betrayal and her plans of revenge against the United Planets, Timber Wolf's disappearance, and Lightning Lad and Saturn Girl's quasi-failed relationship.
Well, he bit off Lightning Lord's finger and didn't swallow it, in the Threeboot, and Lightning Lord was going to kill him with that finger. Matter-Eater Lad wasn't a member then, either.
Note that during the Great Darkness saga, Bouncing Boy successfully knocked down Daxamites. Granted, they were mind controlled and thus not at peak efficiency, but still. Daxamites.
On some occasions, Substitute Heroes would be inducted to the Legion, such as Night Lass and Polar Boy, because it turned out their powers weren't so useless after all.
In the Reboot, it would actually be retconned that the Legion tryouts only partially test for the viability of the applicant's power. Yes, having a power that is utterly useless or too dangerous to your allies is one way of being rejected. The other thing they test for is mental stability (hence why Reboot Chlorophyll Lad is still rejected; he's considered too delusional) — the so-called "Justice League of Earth" were all booted out specifically because the tests revealed they had, in essence, psyches that could easily lead them to abuse their positions and powers.
With Great Power Comes Great Insanity: Brainiac 5 and Matter-Eater Lad after he eats the Miracle Machine. The Time Trapper is similarly revealed to be a victim of this at the end of v4.
Postboot, Shrinking Violet / Leviathan II during her Emerald Empress phase and Element Lad during the original Legion Lost (though the latter may be a better example of Driven to Villainy).
Seems to be a fairly common occurrence with the Emerald Empresses.
The Woman Wearing the Queenly Mask: Princess Projectra left the Legion because of this following the (first) death of her husband, Karate Kid and the need to rebuild her homeworld. She later returned to the team in secret, under the guise of Sensor Girl.
Happens to Shrinking Violet in phases. She starts off as exactly the cliche her name suggests. In the early 1980s, she's kidnapped and replaced with a shape shifter. When she returns she's Darker and Edgier from the experience. Later on, she gets drafted, experiences War Is Hell first hand, and comes out the other side as a Martial Pacifist.
Taken in a different direction following the Zero Hour reboot. See the above entry for Beware the Quiet Ones.
X-Ray Vision: Ultra Boy, Superboy, Supergirl, Mon-el/Valor, Andromeda, Dev-em and his clones, and every empowered Daxamite. Even Wildfire had the power briefly.
Yin-Yang Clash: The Time Trapper versus the Infinite Man in v3 #50, each representing a fundamentally different model of how time works.
Superboy, of course, although that serves primarily as background material for his role in Legion stories.
Element Lad's origin story involves the destruction of his home world of Trom and most of its inhabitants in most versions of his origin.
Both Superboy (the Kon-El clone version, not the original) and Supergirl were stranded in the 31st century during their stints with the team in the postboot and threeboot runs, respectively.
The postboot team, later renamed the Wanderers, are the sole survivors of their entire universe.
On a less apocalyptic note, in the original continuity, members of the Green Lantern Corps were prohibited from operating on Earth. When Legion supporting cast member and Earth native Rond Vidar was outed as a Green Lantern, he was forced to leave for parts unknown, unable to return.
Numerous story arcs have been written about Legionnaires being trapped in space and/or time: Legion Lost (both series), the early 1990s Timber Wolf miniseries, and an extended story arc running through Legion of Super-Heroes V4 in the late 1990s.
Subverted by the post-Zero Hour Chameleon Boy- he can't speak Interlac for a good long while at first, but the distrust he gets as a shapeshifter is depicted as a bad thing (prejudice = not cool, guys). And then they reveal how long it actually took him to learn the language, and that he's been keeping it a secret as part of a sting operation...
The 2007 relaunch under Geoff Johns gave team financier R.J. Brande a thick German accent, despite the fact that it was presented as a direct continuation of the 1980s version of the team, where he had no problem speaking unaccented Interlac. This was later lampshaded by Brainiac 5 as one of Brande's personality quirks in an issue of Adventure Comics.