Zexion

Zexion formerly known as Zantou was the main protagonist of the first half of the series and was believed to be Master Splinter's son until he found he was a clone of the real Zantou and he went to destoryed half of the Dark Water members and allowed the turtles to destroy him so the real Zantou will be free and allowed the turtles to destory the remaing members of Dark Water and used to rank number 6 in the Dark Water and is Zantou's cunning personality.