During the fourth season, Karai continues to lead the Foot Clan as a female Shredder, Hun turns the Purple Dragons into a crime syndicate, and Baxter Stockman works for Agent John Bishop's group. Towards the end of the fourth season, the series undergoes a format change as the Turtles would be recruited by the Ninja Tribunal to use new mystic abilities to combat another version of the Shredder where this one is labeled as the original Shredder before Ch'rell assumed his identity. Season five would be the last to use the original character designs and animation style with its plot concluding the series' main storyline.