Teenage Mutant Ninja Turtles (2003) (2003)

S6E23 DNA Is Thicker Than Water

Dark Leo sets out to validate his worth by infiltrating the Turtles' ranks, aiming to dismantle their unity from the inside. As he sows seeds of discord and manipulates their trust, the Turtles must confront not only their foe but also the shadows lurking within their own family. The stakes rise as loyalties are tested and the bond between brothers is put to the ultimate challenge. Will they recognize the danger in time to save themselves, or will Dark Leo's treachery tear them apart?