This story contains a lead-in into season 2's story arc, so I want to cover that arc in this epilogue so I don't leave you hanging.
Throughout season 2 Mortu and Donatello experiment with Anti-Mutagens based on analyses of the original. An early form grants the recently mutated superhero-wannabe, the Pulverizer, more intelligence than his human and blob forms and the ability to temporarily reshape his body into a humanoid. With some modifications to the containment barrel he's in, he becomes the Mutagen Man. With Miwa now on their side and some DNA donated by Leatherhead as reference, the turtles try to stop the Kraang despite the new bodies. Eventually, after two total failed experiments where April turned into a fish and a wasp, respectively, they returned April to her human state. The turtles and Shredder get into a big showdown and Shredder is ultimately defeated and killed when he tries to blow himself and the turtles up. However a Foot Clan scientist take some of Shredder's DNA from Ground Zero of the explosion and sees about bringing him back. Dimension X is rendered inhabitable again by Utrom scientists and the Time Sceptre, the artifact the Kraang were after, was seemingly destroyed.
