Reactive Evolution is a power that allows a character to automatically adapt to enemy attacks and hostile environments, and/or to grow stronger from sustained damage.
The name is somewhat of a misnomer, since although it is named after biological evolution, real evolution happens to populations, not individuals.
This power is one of the abilities most known for being considered a no-limits fallacy. However, it can still be quantified by the demonstrated feats, and a reasonable limit can usually be extrapolated.
- ARMS Users (Project ARMS)
- Amazo and Doomsday (DC Comics)
- Ryuko Matoi (Kill la Kill)
- Garou (One Punch Man)
- Goku Black (Dragon Ball Super)
- Berserker's God Hand (Fate/Stay Night)
- The Borg (Star Trek)
- Ultimate Lifeform Kars, (JoJo's Bizarre Adventure)
- Darwin and The Fury (Marvel Comics) (In Darwin's case at least, his powers are designed to preserve his own life; Encountering an enemy that is beyond his ability to contend with has on at least on occasion resulted in him developing teleportation abilities, which he used to escape to a safe distance)
- Kecleon from Pokemon (Special ability Color Change allows it to change its type to that of the last attack used on it)
- Ifurita, from El-Hazard
- Meta Cooler (Dragon Ball)
- Nurarihyon from Gantz
- SCP-682 (SCP Foundation)
- Vajra in Macross Frontier can gradually adapt to any weapon, even Reaction warheads.