'Finish Him' comes from the Mortal Kombat game series, where an announcer calls it near the end of a match to signal a finishing move opportunity. The phrase became one of the franchise's most recognizable audio cues and spread far beyond fighting games through compilations, parody edits and meme videos. It still gets used because the meaning is instantly clear even out of context: someone is cornered, a decisive moment is coming, and the next beat should land hard.