The Pentakill call comes from League of Legends, where the in-game announcer says it when one player gets five kills in a row within the required window. As competitive clips and streaming highlights spread online, the line became a staple in gaming edits and memes. It still gets reused because the meaning is instantly clear to many players: complete domination. Even in non-gaming posts, people recognize it as shorthand for a perfect sweep or an absurdly one-sided win.