In a Shared Universe setting, big stories often turn into Intercontinuity Crossovers or at least Bat Family Crossovers. Alternatively, a big crossover always needs C-List Fodder or perhaps sets up a Retool of the universe or the properties in it. As a result, crossovers provide a lot of opportunities for the Grand Finale of a particular series that's up for cancellation or revamping. By bringing in elements from the wider universe or from another series, the last storyline can achieve a sense of scale. In particular, works that end quickly for various reasons sometimes need to borrow existing elements or events because they don't have all the internal elements for a Grand Finale in place yet.
While primarily a Comic Book trope because of the prevalence of the Shared Universe in that medium, the Crossover Finale idea shows up in other media from time to to time. In television, this frequently overlaps with Back for the Finale, as characters from the Spin-Off or the parent series show up to usher out their sibling show.
A Sister Trope to Fully Absorbed Finale; if the Grand Finale takes place entirely in a Crossover Mini Series or another series, it fits that trope, not this one. However, if the early installments are billed as portions of the series that's ending, the fact that the final installment happens elsewhere need not disqualify an example. For that reason, be especially careful to avoid Zero-Context Examples when adding entries. Occasionally, this trope works as an Inverted Trope to Fully Absorbed Finale, as characters from another series show up and "take over'' the Grand Finale storyline.
This is an Ending Trope, and as such will contain lots of unmarked spoilers!
- The last two episodes of Digimon Xros Wars: The Young Hunters Leaping Through Time have Taichi, Yamato, Daisuke, Ken, Takato, Takuya and Masaru coming together with some spacetime thing to fight against Quartzmon. (It's not only them: Mimi and Ruki appeared some episodes before, the main episode itself includes brief cameos of Jou, Tentomon and Chackmon with Takeru, Hikari, Ryo, Miyako and others appearing as shilouettes in the beginning, while it's stated they're fighting Quartzmon's minions around the world).
- DC Comics is perhaps the primary example of this trope. From the 1980s to the 1990s, they had annual Crisis Crossover stories which launched books. Because titles were renewed on a yearly basis, a title spinning out of one annual crossover was often ended during a tie-in to the next one. In particular, several books launched during Zero Hour! were cancelled during Underworld Unleashed tie-ins.
- The 1996 Manhunter series used Underworld Unleashed to explain the depowering of the main character, Chase Lawler, thus bringing his adventures to a close. Similarly, Primal Force used the same crossover to give the characters a Battle Royale With Cheese against Lord Satanus and their only recurring villain, Cataclysm as a segue to a Distant Finale with the team disbanding after that clash.
- Justice League of America:
- The original series ended with a Story Arc tying in to the Legends crossover, showing how the loss of legal and public support for superheroes left the title's characters vulnerable to a murderous attack by one of their old enemies.
- Likewise, the death knell for JLA started with Identity Crisis, culminating in the events of Infinite Crisis seeing that version of the League shut down between word of the Power Pact's mindwiping getting out and the Big Three's falling out from Wonder Woman killing Max Lord.
- Hawk and Dove provides an unusual example. While the book also had a Fully Absorbed Grand Finale in the Armageddon 2001 crossover, the final issues of the regular series showed the title characters ending their partnership against the backdrop of the War of the Gods crossover.
- Surprisingly averted by the granddaddy of all crossover comics, Crisis on Infinite Earths, during which most titles either had a Fully Absorbed Finale in the Crisis series itself or trundled along for awhile afterwards until their Post-Crisis Retool or cancellation came along.
- A number of late 1990s titles, notably Chase, Chronos, and an ill-fated relaunch of The Creeper finished off with Grand Finale or Distant Finale stories in their #1,000,000 issues as part of the DC One Million crossover.
- While most books relaunched as part of the New 52 wrapped up on their own ahead of Flashpoint, two series, Booster Gold and The Flash, ended by tying directly into the event because it dovetailed with their time-travel based premises.
- Marvel Comics has done this twice over to The Avengers and related titles:
- "Avengers Disassembled" was more of a Cross Through, ending the original incarnation of the main title and the ongoing volumes of Iron Man, Thor, and both ongoing Captain America series using tie-ins to the Scarlet Witch's reality manipulations. While most of the books were quickly relaunched afterwards, Thor seemingly died at the end of his Disassembled storyline and didn't come back for several years.
- Over a decade earlier, Marvel used the Onslaught crossover to end the same books listed above, as well as Fantastic Four, so that the books could be relaunched with a different shared continuity and helmed by the Image Comics crew of Jim Lee and Rob Liefeld. When Marvel decided to bring the "Heroes Reborn" books back with the Heroes Return miniseries, all four series spent their final issues on an Intercontinuity Crossover with Lee's Wildstorm Universe characters called "World War Three" before the opportunity vanished.
- Another casualty of Onslaught was the short-lived Green Goblin series about Phil Urich as a heroic Goblin. The Sentinel attack during Onslaught destroyed Phil's stolen Goblin equipment, which he didn't know how to reconstruct on his own, and thereby ended his career as a hero.
- The 2013 volumes of Cable and X-Force and Uncanny X-Force ended with a crossover storyline between the two books.
- A Paratext example: In 1968, two of Marvel Comics' anthology series became solo series for two of their stars: Tales to Astonish became The Incredible Hulk and Tales of Suspense became Captain America. Meanwhile the two co-starring characters in those books, Prince Namor the Sub-Mariner and Iron Man, got new books starting with #1. To assist in the transition, there was a one-issue comic Iron Man & Sub-Mariner, which contained the second half of each of their stories which had started in the previous issues of Suspense and Astonish, respectively, allowing their solo books to launch a month later than their respective co-stars'.
- The final issues of the first volumes of Dark Avengers, New Avengers, and Mighty Avengers ended with tie-ins to Siege, because the event radically altered the status quo crucial to these books' premises. (New Avengers also had a special finale one-shot tying into the same event.) The final issue of Dark Avengers and the New Avengers: Finale one shot each provide epilogues to the crossover Mini Series.
- The Ultimates ended its best-known run by Mark Millar and Bryan Hitch by bringing in virtually every other hero in the Ultimate Universe, normally relatively self-contained, for the final battle against Comic Book/Loki and the monsters of Asgard.
- Not long afterwards, all of the original series in the Ultimate Universe ended with the Ultimatum crossover.
- And now they're doing it again, relaunching every current title and ending certain series entirely with the Cataclsym crossover featuring the mainstream Marvel Universe version of Galactus merging with his Ultimate counterpart to menace everyone.
- Not long afterwards, all of the original series in the Ultimate Universe ended with the Ultimatum crossover.
- The Marvel Comics miniseries Druid ended when the characters from Hellstorm showed up and killed Doctor Druid, the Villain Protagonist.
- The finale of the 1970s Luke Cage: Hero for Hire series in the 1970s brought in Iron Fist and his supporting cast, revealing that Iron Fist's archfoe had he evidence to clear Cage's name (and end the "framed fugitive" plotline of Cage's solo adventures). The book was then relaunched as Power Man and Iron Fist.
- By contrast, Iron Fist finished its Seventies run with a simple Fully Absorbed Finale in Marvel Team-Up, where Spider-Man appears mostly to get swatted out of the way while IF has his final duel with his Arch-Enemy, the Steel Serpent. The crossover elements themselves add little or nothing to the finale, which is what keeps it out of this trope.
- Marvel's Avengers Assemble title was basically reserved as the series for crossover stories, and fittingly ended with a tie-in to the company's "Inhumanity" event.
- Uncanny Avengers ended its run by setting up the AXIS crossover, after which it will be relaunched as part of a Retool.
- Shinnen New Year serves to be Ford1114 and Kanius's own take of continuing Guilty Crown as a Mega Crossover by having their fan-stories and popular culture making appearances. It is also Ford1114's final story to deliver all he's got for this sendoff and for celebrating Guilty Crown's 5th anniversary in 2016.
- The series 4 finale for Doctor Who, which was also the last regular-season episode for David Tennant, brought the Tenth Doctor together with characters from spinoffs Torchwood and The Sarah Jane Adventures to stop the Daleks destroying all of reality. When the Tenth Doctor gets his sendoff — along with showrunner Russell T Davies — in "The End of Time'', he briefly visits Jack and Sarah Jane as well.
- Star Trek: Enterprise infamously had a finale which used a Next Generation crossover, showing that at least some of what we had seen was a Holodeck recreation of the original events.
- Overlapping with Fully Absorbed Finale, the Chris Carter show Millennium finished up in an episode of The X-Files despite there being no previous indication that the two were part of a Shared Universe.
- The Grand Finale of Buffy the Vampire Slayer brought back Angel in its final episodes to provide the heroes with a MacGuffin that figured in the final battle. In turn, Spike and Harmony became regulars for the final season of Angel, though the actual finale to the televised Buffyverse didn't cross anyone over because Joss Whedon wanted the finale to be about Angel, not Buffy.
- A few of the Showa-era Kamen Rider series had classic Riders showing up at the end to help the hero save the day, Kamen Rider BLACK RX being a notable one as the last one. Kamen Rider Wizard had a Post-Script Two-Parter that brought in Kamen Rider Decade, cameo'd the other Heisei Riders and introduced Kamen Rider Gaim. This was repeated for the final episode of Kamen Rider Drive, where Kamen Rider Ghost makes his debut TV appearance; and the final episode of Kamen Rider Ghost, where Kamen Rider Ex-Aid and his prototype, Kamen Rider Genm, make their debut TV appearances. Kamen Rider Zi-O, the final series of the franchise's Heisei era, is a season-long crossover with every past Heisei series.
- Power Rangers
- The finale of Power Rangers in Space features all of the villainous factions from the past five seasons (Rita and Lord Zedd, the Machine Empire, and Divatox). The Mighty Morphin Alien Rangers, the Gold Zeo Ranger, Blue Senturion, and the Phantom Ranger all make appearances. The Quantrons and the Pirahnatrons (Astronema and Divatox's footsoldiers, respectively) are seen working together during the attack on Earth.
- The finale of Power Rangers Super Megaforce featured a crossover with many Rangers of seasons past, including the return of fan-favorite Tommy Oliver.
- Doubling as a Fully Absorbed Finale, The Flash gets concluded long after the series ended with the Crisis on Infinite Earths crossover event, in which Barry Allen of Earth-90 dies after sacrificing himself to stop the antimatter wave.
- Another series that concluded with Crisis on Infinite Earths is Arrow; although there are two more episodes after the crossover, the first is a Poorly Disguised Pilot for a potential spin-off, while the other is the Grand Finale that addresses the aftermath of the crossover event.
- Cow and Chicken/I Am Weasel: Although I Am Weasel was a Show Within a Show tagged at the end of Cow and Chicken, the Red Guy (with some other rare occasions) was usually the only Crossover character from Cow and Chicken to appear regularly on I Am Weasel. However, in Cow and Chicken 's final episode, the I Am Weasel segment dealt with Weasel and Baboon basically crossing over into Cow and Chicken 's universe to investigate the disappearance of not only them, but pretty much all of the characters from that universe, including Teacher being half-erased, and Flem and Earl being reduced to only ink outlines, and discover that Red Guy had been literally rubbing everyone out (with a giant pencil eraser) in an act of revenge of not being given his own cartoon show. It turns out to be All Just a Dream by Cow.