The Kaioken is a fighting technique from Dragon Ball Z, created by King Kai and first used by Goku after training on King Kai's planet. It briefly boosts strength, speed and senses at a cost to the body, and became one of the series' early signature power-ups before Super Saiyan arrived. This English line circulates on soundboards as a compact shorthand for that moment, reused in fan edits, gaming clips and memes whenever someone is about to stop holding back and try much harder.