KJ ult comes from Roblox fighting gameplay, where it is tied to KJ's ultimate move and is clipped by players to reuse in their own videos. As clips of dramatic finishes and one-hit knockouts spread on short-form video and Roblox edit channels, the short impact became a shorthand for an overpowered attack landing. Creators keep using it because it is instantly recognisable to fans of the game, works in under a second, and fits any moment that needs a sudden burst of power without dialogue or explanation.