As the series progresses, his rivalry with Donatello is lessened, and he becomes closer to the whole team in general. In season three's "Casey Jones VS. The Underworld" Casey decides to start hunting crime on his own and eventually meets his new own archenemy, Hun, the new leader of the Purple Dragons. He is defeated, at first, but later defeats Hun and prolongs Shredder's plans. He is later one of only six inhabitants of Earth-the others being April and the Turtles-to be rescued before the planet is consumed by an artificial black hole.