Teenage Mutant Ninja Turtles (2003) (2003)

S4E16 Prodigal Son

Leonardo comes back from Japan only to discover that the lair is in shambles and his family is missing. As he searches for answers, he uncovers that the Foot Clan has regained their power, now under the command of Karai. Believed to be deceased by the Foot, Leo decides to apply everything he has learned from the Ancient One to confront this new threat and rescue his loved ones.