Michelangelo‘s choice to visit Slash alerts the Turtles to Old Hob‘s genetic experimentation (resulting in the humorous but ridiculous Pigeon Pete) and the kidnapping of a Stockgen scientist who the mutant believes can make things work better the second time around in his attempt to create his own mutant army.
The confusion after releasing Lindsey leads to the reveal of Old Hob’s possession of Splinter‘s blood and just what it can do as Slash’s limited intelligence and understanding grows quickly to mirror that of his brothers after choosing to inject it into his body to prove he’s a true hero. The change in the character may loose Mikey a playful pal, but it opens up new possibilities for Slash moving forward (not all of which might be good for the team once Slash begins to think for himself).
Offering a little more of Angel in Harold‘s Exo-Suit, the B-story sends the former Purple Dragon to the aid of Casey whose father Hun and his goons plan to beat to death on the grave of Casey’s mother. Not exactly a Hallmark moment. Worth a look.