Sometimes, creators want to give their long-running series a fresh start, so they decide to make a Continuity Reboot. However, they sometimes don't want to just make a completely new reality for their series, instead making the reboot an actual part of the continuing storyline. In cases like this, one tool the creators have is to use a character to explain the reboot. Hence, the Continuity Rebooter.
A Continuity Rebooter is a character who, by some form of applied phlebotinum, causes either an Alternate Continuity to a work to be formed or the current continuity to be replaced with a new one. The character, whether intentionally or accidentally, changes his reality in such a way that the world becomes a fundamentally different place.
However, this trope doesn't refer to a character doing this as part of an Elseworld or What If? story, as those are non-canonical. It's also not any event which just lasts a little while and is eliminated with a Snap Back or the use of the Reset Button. A Continuity Rebooter must cause a long-lasting change in the series' continuity or create a long-lasting and well-explored alternate continuity to qualify, and that change must be part of the main canon. A series revolving around Time Travel doesn't count, since, well, that is a fundamental part of the plot (so no, Back to the Future isn't an example). However, a series that doesn't normally involve time travel and uses it as a device to change continuity would count if the change sticks.
Another factor in a character being a Continuity Rebooter is that the Continuity Reboot is NOT a complete one. The previous continuity is not wholly discarded, simply modified radically. In fact, a major plot point common to Continuity Rebooters is that the Rebooter remembers the previous reality. This also allows the series' creators to bring back fan-favorite characters and ideas from the previous reality to the new one, or even to bring the old reality back wholly (although never immediately). The new reality depends on the events of the previous one to exist, it's not invented wholecloth (like, say, an Ultimate Universe).
A character is a Continuity Rebooter if:
- a Continuity Reboot or Alternate Universe is formed,
- the reboot can be specifically attributed to the character's actions,
- the previous continuity is not wholly discarded and the new reality depends on events from the previous one, and
- the change sticks and is not immediately eliminated.
Usually, the character's mucking with the series' continuity is the plot behind a Crisis Crossover, and he uses the Timey-Wimey Ball or some kind of magic or cosmic plot device for the change. The character can alternatively be a Reality Warper who somehow changes his universe's events.
MASSIVE spoilers to follow:
- Enrico Pucci in JoJo's Bizarre Adventure: Stone Ocean reboots the universe in the climax using Made in Heaven, and the next two parts, Steel Ball Run and JoJolion, are set in a new universe with characters, places and situations similar but different to their original counterparts. However, this universe has never been directly said to be a result of Pucci's actions, and Word of God even says the Morioh of Part 4 and Part 8 aren't connected by time and space (and therefore not a "reboot" of the original town).
- DC Comics has had a few of this kind of character, usually using a Crisis Crossover as the point for the changes to occur. The changes tend to be very long-lasting. Examples include:
- The Anti-Monitor during Crisis on Infinite Earths, which led to the first true reboot of the DCU. He destroys The Multiverse and all realities merge into one.
- Hal Jordan during Zero Hour!. Less extreme (and less well-received) than Crisis.
- Hoo boy, Superboy Prime during Infinite Crisis, causing the second big reboot of the DCU and setting up MANY a later crisis crossover. Basically the Anti-Anti-Monitor: The Multiverse comes back.
- Either Barry Allen or Pandora in Flashpoint, leading to the New 52. Barry was the one to actually merge the DCU with WildStorm and Vertigo Comics timelines, but it was Pandora that got him to do it.
- It's eventually revealed that Doctor Manhattan from Watchmen is the one responsible for the New 52 timeline.
- Convergence has Pre-Zero Hour! Parallax and Pre-Flashpoint Superman volunteer to be sent to the past in place of the Doomed by Canon Pre-Crisis Supergirl and Pre-Crisis Barry Allen. This results in a dramatic change in the outcome of the first Crisis, and now the original multiverse exists alongside the New 52 multiverse.
- Marvel has a few characters of this stripe too, although the changes are nowhere near as wide-ranging as DC's and are usually limited to alternate continuities, with a few exceptions:
- Legion in Age of Apocalypse. Legion travels back in time to kill Magneto, but kills Professor Xavier instead. The resultant world's... not a nice place.
- Onslaught and Franklin Richards in Heroes Reborn. Onslaught apparently kills the major heroes of the Marvel U, but Franklin Richards actually uses his powers to transport them to an alternate reality, then brings them back.
- Scarlet Witch in House of M, causing the Decimation of the mutants, which is the cause of many following events in the Marvel U.
- Mephisto (to MANY a fan's consternation) in One More Day.
- Sonic and Dr. Eggman become this in Sonic the Hedgehog (Archie Comics). Eggman is the one who makes the initial changes ("Sonic: Genesis", Sonic the Hedgehog/Mega Man: Worlds Collide) and Sonic's the one to put it back. However, both times Sonic does it, he messes something up (the second time wasn't his fault, though - Eggman interfered.)
- Star Trek (2009): Spock and Nero. Spock's failure to prevent a massive Negative Space Wedgie from forming causes him and Nero to go back into the past, creating an Alternate Timeline that runs parallel to the original. Every change from the original continuity to the rebooted continuity is attributed to Nero's late-24th century Romulan cargo ship showing up in the early 23rd century, which only happens due to Spock's failure to save Nero's planet.
- Wolverine in X-Men: Days of Future Past. His warnings led Professor X and Magneto to stop Mystique from causing the DOFP timeline... but doing so before the days of the original trilogy mean that the present changes as much as the future. Most notably, everything fans disliked about X-Men: The Last Stand and X-Men Origins: Wolverine never happened, overlapping with Author's Saving Throw.
- Similar to the comics counterpart, in The Flash (2014) Barry goes back in time to save his mom, resulting in the Flashpoint timeline. This version is Lighter and Softer instead of the utter hell of the comics version, and he only restores time when Wally West is mortally wounded. He restores an altered version of reality, causing changes in the lives of the people around him (yes, they learn. Yes, they take it about as badly as you think.) And, as in the comics, Barry learns that everything isn't his fault (though it's not quite to the extent of "a totally unrelated reality-warping character really did it" like the comics. Rather, when we learn Savitar's deal it's clear it would have happened anyway, and just because Barry didn't know of Caitlin's An Ice Person powers until after the reset doesn't mean for sure that it's the cause of her stint as Killer Frost. With things like this he learns to let go of It's All My Fault mode and accept the current world.)
- Raiden in Mortal Kombat 9. At the end of Armageddon, Shao Kahn is triumphant, and the universe is headed for destruction. In a last act of godly influence, Raiden sends messages to his past self to try and avoid the Bad Future. This explains how the game is a remake of the first three games, yet a proper sequel at the same time.
- However Mortal Kombat 11 reveals that Kronika, the Goddess of time in the MK universe, has actually been doing this several times even way before the events of the first game largely as a way to turn Raiden and Liu Kang against each other as the two are the major threats to her plan to create a universe how she wants it, even stating that in some cases Raiden finding out in previous timelines hasn't deterred her. However in this reiteration Raiden gives up his god power to Liu Kang (the one that got pulled from the past, not the one in this timeline who turned evil when he became a revenant) who proceeds to (canonically) defeat Kronika and take control of the hourglass. This time intending to make a new timeline without her influence, thus being the rebooter for the next installment.
- Shu Shirakawa in Super Robot Wars Alpha Gaiden. His Neo Granzon causes the heroes to travel through time thousands of years, resulting in the world being a wasteland(as the heroes were not there in the past to save it).
- Tatsuya in Persona 2. At the end of Innocent Sin, the world is on countdown to the apocalypse, and Philemon offers the main characters the chance to have their memories erased and time rewound to avoid it. However, Tatsuya, at the last second, relents on losing the memories of his comrades, and so the continuity of Eternal Punishment forms, in which Tatsuya is the only one who remembers what happened in Innocent Sin and Nyarlathotep has another chance at destroying the world.
- Serge in Chrono Cross. When young, he was attacked by a panther, and at that moment the universe split in two: his current reality and another reality in which he died from the panther's attack. A big part of the game's plot is WHY he's so important to both universes that his near-death experience causes such a dissonance between them. He also reboots the events of Chrono Trigger, as his existence and actions actually cause Crono and his friends' actions in the first game to have been all in vain.
- Lezard Valeth in Valkyrie Profile 2 Silmeria. You actually discover in the game that the Lezard you've been using is actually the previous game's Lezard, who traveled back in time to put his plan to make Lenneth his into motion from MUCH further back than in the original timeline, hence the game is already a reboot from the moment you start playing. Even Lenneth herself eventually appears and mentions how Lezard's causing changes in the timeline, and joins the past heroes in an attempt to stop him.
- AZ from Pokémon X and Y is revealed to be this in Omega Ruby and Alpha Sapphire. His use of the Ultimate Weapon is implied to have created an alternate timeline, one in which he did and Mega Evolution exists (Generation VI and onwards), and one where he did not and it doesn't (pre-Gen VI). Pokémon Sun and Moon reinforces this as Anabel (who appeared in Pokémon Emerald but not the remakes) explicitly comes from another universe (and her battle music is ripped straight from Emerald, implying she comes from the original universe).
- A recurring element within the Shinza Bansho Series is that each major entry ends with someone rising to the Throne and becoming the new ruling God of the multiverse after the old one has been slain, followed by its complete reformation according to whatever law the new God craves. As a result, each entry tend to be vastly different in setting, tone and style or even genre with very little to do with the other entries. In general, this rule tend to be the one constant. As of this writing, Nerose Satanel, Marie, Hirume and Magsarion are those that have been shown to have accomplished this, while Mithra, Mercurius and Hajun did so off-screen.