This clip comes from the in-game announcer in League of Legends, where a pentakill means one champion has taken all five enemy champions. Announcer lines like this became familiar far beyond the game through highlight videos, streamer compilations and short meme edits. It remains popular because even people who do not play LoL can understand the meaning instantly: one person just wiped out the whole team. The closest related gaming cue in meme culture is enemy spotted, another short callout used for fast context.