Complex sentence: Leonardo again leads the team in Nickelodeon's 3D computer-animated series, voiced by actor Jason Biggs up until "The Wrath of Tiger Claw", Dominic Catrambone for the remainder of the second season and Seth Green assumed the role in the third season.
Split into simpler sentences: Leonardo again leads the team in Nickelodeon's 3D computer-animated series. He was voiced by actor Jason Biggs up until "The Wrath of Tiger Claw", Dominic Catrambone for the remainder of the second season and Seth Green in the third season.