Clark Luthor / Earth-2 Clark / Ultraman (Tom Welling)
- "This world won't know what hit it."
Earth-2's Kal-El, who was found by Lionel Luthor rather than the Kents. Raised by a Social Darwinist father, he's a cold-blooded sociopath who can't keep it in his pants and commits murder as a matter of course. He briefly escapes to Earth-1, where Tess, Oliver and Lois fight him to a draw; he is then transported back.
- Ax-Crazy: He casually admits that not having blood on his hands before lunchtime "doesn't feel right."
- Badass Longcoat: Wears one when he attacks Watchtower in "Luthor."
- Bastard Understudy: To Earth-2 Lionel. Social Darwinist that he is, Lionel's disappointed that Clark hasn't made his move yet.
- BrotherSister Incest: With adoptive sister Earth-2 Tess.
- The Bully: Was apparently one in school.
- Cain and Abel: With Earth-2 Lex in his Backstory. Their rivalry got Lex killed and left Clark with a permanent scar on his arm.
- The Dragon: To Earth-2 Lionel, who's upset he isn't The Starscream.
- Evil Twin: Clark Kent's.
- For the Evulz: He kills people for fun, and nonchalantly admits that it feels strange "not having blood on his hands before lunch."
- Good Scars, Evil Scars: Has a big scar on one arm, which he claims to have been caused by Earth-2 Lex using Gold Kryptonite.
- HeelFace Turn: Implied in "Kent."
- Karma Houdini: Receives no punishment for his actions.
- Lack of Empathy: Displays none.
- Man of Wealth and Taste: Always dressed to the nines.
- No Ending: It is unknown whether Clark Luthor/Ultraman survived the destruction of Earth-2 or died alongside the others, though according to Bryan Q. Miller a scene cut from the final script for Kent has Ultraman confronted and attacked by the Earth-2 versions of Chloe Sullivan, Aquaman, Martian Manhunter and Cyborg at his respective version of the Fortress of Solitude, while armed with blue kryptonite-based weapons. He would attempt convincing his enemies he has changed for the better to no avail. Luthor is delivered a final strike from Chloe, which kills him.
- Overlord Jr.: And he's pretty resentful about it.
- Psycho for Hire: He's implied to be his father's assassin and complains at one point that it feels strange "not having blood on my hands before lunch." He's in for the privilege and the kicks, not whatever Earth-2 Lionel pays him.
- Psychotic Smirk: His default expression.
- Really Gets Around: Implied.
- Scars Are Forever: Courtesy of Earth-2 Lex and Gold Kryptonite."There's no take-backs with Gold K. Lex really knew how to leave an impression, didn't he?"
- Shadow Archetype: He is more or less what Earth-1 Clark would be if he was raised by the Earth-1 Luthors.
- The Sociopath: A murderer without empathy.
- Three-Way Sex: When Earth-1 Clark switches places with him in "Luthor," he wakes up in bed with two hookers.
- Villainous Incest: With Earth-2 Tess.
Earth-2 Lionel Luthor (John Glover)
Exactly What It Says on the Tin. He's Earth-2's Lionel, who found baby Kal-El and raised him as his own alongside Lex and Tess. Having murdered all the other members of Veritas, Lionel went on to fuse LuthorCorp with the Metropolis underworld, gaining control of the city and possibly the entire planet. An ice-cold Social Darwinist, he has raised each of his children to be a Bastard Understudy, training them to plot against one another and himself.
First encountered by Clark during his trip to Earth-2 in Season 10's "Luthor," Earth-2 Lionel's acquisition of ultimate power is revealed to have made him far more evil than his Earth-1 counterpart ever dreamed of being. After trying and failing to murder Earth-1 Clark, he escaped to Earth-1, where he impersonated the original Lionel, seized control of LuthorCorp from Tess and Oliver, and resumed his search for an heir, sparking a war between himself on the one hand, and Tess and Clark on the other for control of Lex's clone Lx-15. Initially, Earth-2 Lionel appears to have the upper hand but Clark ultimately wins out, with Lx-15 adopting the identity of "Conner Kent" instead of "Alexander Luthor."
Driven from power following this fiasco, Earth-2 Lionel flees to Lex's grave where he encounters Darkseid and rejects a deal to resurrect Lex. In the series finale, he later kidnaps Tess and tries to extract her heart to power Lx-0, a perfect clone of Lex. Tess escapes and shoots Earth-2 Lionel, who uses his last breath to accept Darkseid's deal, giving up his own heart and soul to resurrect the real Lex, and becoming Darkseid's vessel. When Darkseid is defeated, Earth-2 Lionel's body dies.
- 0% Approval Rating: On Earth-2. On Earth-1, he's a lot more circumspect.
- Abusive Dad: Earth-2 Lionel! Making the real thing look like a nice guy!
- Archnemesis Dad: To Alexander and our Tess after making his way to Earth-1. He drugs the former with Red Kryptonite and actively attempts to kill the latter.
- Arson, Murder, and Admiration: His reaction upon discovering that Earth-1 Lex murdered Earth-1 Lionel. He takes it as an indication that the boy is a true Luthor.
- Back for the Finale: Looks right at the camera and says: "Wouldn't want to miss how it all turns out".
- Ax-Crazy: As an extreme, psychotic Social Darwinist, Earth-2 Lionel has no problem with murdering countless people. And he's actually angry at Earth-2 Clark for not offing him, which he believes Clark is entitled and obligated to do! He's just that Ax-Crazy!
- Beard of Evil: Starts out with the same small beard that our Lionel had; by the time "Finale" rolls around, it's pushing Santa Claus-ish.
- Breaking the Fourth Wall: After escaping to Earth-1, he looks straight at the camera and tells the audience that he "wouldn't want to miss how it all turns out."
- Broken Ace: Has all of the original Lionel's problems, plus some. This really becomes apparent in the later episodes when his hunt for an heir turns frantic.
- The Chessmaster: He relies on emotional manipulation to a greater degree than his Earth-1 counterpart did, but still holds this title if the weeks he spent getting his Earth-1 LuthorCorp takeover in motion are any indicator. Regardless of universe, he's still the MB.
- The Coats Are Off: During his beatdown of Clark.
- Corrupt Corporate Executive: He transformed LuthorCorp into the most powerful entity on Earth-2. He's more or less implied to be a CEO version of The Emperor. After escaping to Earth-1, he's briefly able to gain control of our LuthorCorp, before losing out to Tess and returning to his Diabolical Mastermind persona.
- The Corrupter: Does his very best to turn Alexander into Lex 2.0, first the normal way, and following the emergence of his Kryptonian abilities, Red Kryptonite. Back on Earth-2, he played this role to Lex, Clark and Tess, pitting them against one another to see who would make the better Bastard Understudy.
- Dead Alternate Counterpart: In Season 10, Lionel Luthor from Earth-2 transplants himself to Earth-1, where that Lionel is dead, and establishes himself as the "real" Lionel Luthor.
- Deal with the Devil: At the end of "Scion," he's seen visiting Lex's grave, saying that he would "give anything I have to bring you back." Cue Darkseid forming in the air ominously in front of him.
- This comes to pass in "Finale."
- Diabolical Mastermind: By fusing LuthorCorp and the Metropolis underworld, and by discovering Clark and his ship (and thus allowing LuthorCorp to achieve vast technological advances by studying Kryptonian tech, to the point where he's able to deactivate the Jor-El AI), he's effectively become the most powerful man on the planet. Takes up this mantle on Earth-1 after losing control of LuthorCorp and Alexander to Tess.
- Even Evil Has Loved Ones: He ultimately decides that he really did love Lex and tries to bring him back once he's on Earth-1. This culminates in the Grand Finale, where he lets Darkseid take his soul and body in exchange for giving life to Lex's perfect clone.
- Evil Genius: Easily the smartest of Season 10's villains.
- Evil Sounds Deep: While serving as Darkseid's host.
- Evil Twin: The Eviler Twin to Earth-1 Lionel. E-1 Lionel died a hero and even when he was evil, was nowhere near as evil as his E2 counterpart.
- The Family That Slays Together: Definitely believes this.
- Faux Affably Evil: Unlike Earth-1 Lionel, the Affably Evil routine is all an act. Earth-2 Lionel is more broken than the real thing ever was.
- Grand Theft Me: Gets this pulled on him by Darkseid in the Grand Finale.
- Hannibal Lecture: Hoo boy! He has just as much talent at Hannibal Lecturing as Earth-1 Lionel...but he's way more evil. Earth-1 Lionel's Hannibal Lectures feel like warm and fuzzy pep talks compared to those of his Ax-Crazy, sociopathic Earth-2 counterpart!
- Shut Up, Hannibal!: After he HannibalLectures Tess for an entire season about how much disdain he has for her and then finally gives a final lecture about how killing her to give her heart to Lex will be the only important role she plays in his life, Tess delivers a pretty effective rebuttal: shooting him in the chest.
- The Heavy: For the second half of Season 10. Darkseid is the Big Bad, and his minions are out there doing dastardly things, but it's Earth-2 Lionel who truly moves the plot.
- Heir Club for Men: He's essentially defined by his search for a Bastard Understudy/heir.
- He's Back: Seized control of LuthorCorp and then announced his return in true Lionel fashion.
- Imposter Forgot One Detail: Loses control of LuthorCorp once more when Tess realizes that everyone in Earth-2 has reversed fingerprints, making it look like he's a fraud impersonating Lionel Luthor with fake DNA results.
- Lack of Empathy: Has less empathy than even Earth-1 Lionel.
- Large Ham: He's so hammy that he even makes Earth-1 Lionel look reserved in comparison, although it makes perfect sense since he's much more mentally unstable.
- Manipulative Bastard: Goes without saying. He ruthlessly manipulates Tess and Alexander for his own ends, going so far as to drug the latter with Red K when mere words won't do it, all while attempting to take advantage of Clark and Martha's remaining affection for the original Lionel. This is Lionel we're talking about after all.
- Man of Wealth and Taste: It's Lionel. What else did you expect? Nice suits, classy furnishings, and no soul.
- No-Holds-Barred Beatdown: Of Clark.
- No Sense of Personal Space: He frequently gets uncomfortably close to Earth-1 Tess.
- Offing the Offspring: Tries it on Clark, may have done it to Earth-2 Tess, definitely let it happen to Earth-2 Lex. After arriving on Earth-1, he eventually tries to cut out our Tess' heart to use in resurrecting Lex (though only because Alexander, his other child, was unavailable).
- Oh, Crap!: He followed Clark back to Earth-1!
- And he has a moment himself in "Finale" just before Tess shoots him.
- Out-Gambitted: Tess eventually gets control of LuthorCorp back from him by proving he's not really Lionel Luthor because his fingerprints are the reverse of Earth-1 Lionel's.
- Save the Villain: Clark is forced to do this after Alexander turns on Earth-2 Lionel in "Beacon."
- Social Darwinist: As demonstrated by the epic Chewing the Scenery moment below. He's actually angry at Earth-2 Clark for not succeeding in killing him.
- It's got to be survival of the fittest. Whether you're on this Earth, or any other, I am the most fit! I will be the survivor!
- The Sociopath: To a far greater degree than the real Lionel, probably because having a super-powered son working as The Dragon allowed Lionel's greed to run even wilder than it did on Earth-1. Not only is he tyrannical, manipulative and downright sadistic, but he lacks all of Earth-1 Lionel's standards to boot. Just watch his interactions with, well, anyone on Earth-1.
- Übermensch: Remade Earth-2 in his own image.
- Villain with Good Publicity: On Earth-1. Less so on Earth-2, where his power allows him to rule through fear despite a 0% Approval Rating.
Earth-2 Lutessa Lena "Tess" Luthor (Cassidy Freeman)
Earth-2's Tess, who was adopted into the family instead of being abandoned. Very much The Unfavorite, she is even more screwed up than the real Tess.
- Bastard Bastard: A whining mess of Parental Issues when compared to the real thing.
- Bastard Understudy: Earth-2 Lionel wants one of his children to betray him, and although his money's on Clark, Tess is in the running.
- Broken Bird: Try Utterly Shattered Bird.
- Cain and Abel: She, like Clark Luthor, is implied to have had a very bad relationship with Lex.
Earth-2 Lex Luthor
Earth-2 Oliver Queen (Justin Hartley)
Earth-2's Oliver Queen, he's a dark-haired duplicate of our Oliver who, thanks to serious self-confidence problems, was never able to become a Superhero. He still tries his best, gathering Kryptonite to kill Ultraman with, and opposing Earth-2 Lionel as best he can. When Clark Kent arrives on Earth-2, he and Oliver get off to a bad start, but eventually reconcile to defeat Lionel and Clark Luthor, giving Oliver the chance to be the hero he's always wanted to be. He is engaged to his Earth's Lois Lane.
- Anti-Hero: He's used every method he can to try and defeat the Luthors and Ultraman, thoroughly breaking himself in the process. It's not enough and he knows it, but he's the only hero this Earth has got.
- Arch-Enemy: Of Lionel and Clark Luthor. Then again, he may well be their only real enemy.
- Badass in a Nice Suit: Lacking a costume, he confronts Clark in his suit and tie.
- Dead Alternate Counterpart: He is killed by Clark Luthor.
- Dropped a Bridge on Him: Killed off-screen, between episodes, by Clark Luthor, who later Karma Houdinis his way out of any real punishment.
- For Want of a Nail: There are no Superheroes on Earth-2, thanks to Oliver never finding any good guys who shared his power and commitment to justice. After all, Bart, A.C. and Victor had all been saved by Clark back on Earth-1 before they could become heroes. On Earth-2, we definitely know for a fact that Clark Luthor wouldn't have done that.
- Hero with Bad Publicity: Drove every farmer in Smallville off their land so he could strip-mine for Green Rocks and take down Ultraman. This did nothing to make him popular with the media.
- Heroic Self-Deprecation: Never became a costumed hero and hates himself for it. He still can't believe Earth-2 Lois couldn't find someone better to become engaged to.
- Ineffectual Loner: Has no friends beyond Lois and, without that kind of support, was never able to become a hero.
- Killed Off for Real: In "Kent."
- La Résistance: He and Lois are this against the Lionel's regime. Unfortunately, they're the only active members of La Résistance that they or the audience are ever aware of.
Earth-2 Lois Lane (Erica Durance)
- Arch-Enemy: To the Luthors.
- Ineffectual Loner: Has no friends other than Oliver. And the Planet's editorial board is definitely not on her side, as they refuse to print any of her exposes about the Luthors, due to their being controlled by Lionel.
- La Résistance: She and Ollie are this against the Luthor regime. Unfortunately, they seem to be in it without anyone else.
Earth-2 Jonathan Kent (John Schneider)
- Dead Alternate Counterpart: Inverted. Earth-1 Jonathan is dead.
- Despair Event Horizon: Hit it when Oliver bought up his land and Martha left him.
- Evil Laugh: Gives a pretty good one after revealing his plan to turn in our Clark (whom he believes to be Clark Luthor) for the reward money.