WARNING: The following contains major spoilers for Teenage Mutant Ninja Turtles: The Last Ronin #4, available now from IDW.
The world of the Teenage Mutant Ninja Turtles has had more than its fair share of incarnations over the years, though none have been as dark as that of The Last Ronin. The neon lit future New York has been overtaken by the Foot Clan, who cast a dark shadow on the populace they have largely crushed underfoot. Amidst the darkness there are still heroes, however, and Michelangelo has just taken on his greatest mission yet as sensei to the next generation of heroes.
Michelangelo may not have taken down Oroku Hiroto singlehandedly as intended, but he did end up discovering the still surviving April O'Neil when rescued by her daughter Casey. As impressive as her quick feet and thinking have been so far, Casey isn't much in a fight from where Mikey is standing when he catches her in the midst of solo training. When given the chance to take a shot at a real deal Ninja Turtle, Casey is initially taken aback, but once the goading starts she is all in on the sparring session. Unfortunately, she isn't much against the elder Michelangelo, whose years of training and ongoing mutation have made him into the deadliest man in any room. Still, not all of Casey's moves are bad. In fact, they might even be good enough to be honed by the Last Ronin himself.
While the series has already driven home how callous and calculating Michelangelo has become over the years, The Last Ronin #4 by Kevin Eastman, Peter Laird, Tom Waltz, Esau & Isaac Escorza, Ben Bishop, Samuel Plata, Luis Antonio Delgado, Shawn Lee, and Bobby Curnow puts all of that grit to surprising use refining the next generation's first hero. Between insults and cheap shots, Mikey picks up on how strong and resilient Casey truly is underneath her ugly, untrained fighting style. That coupled with the innate connection the two have as parts of the same sort of family is more than reason enough for Michelangelo to offer Casey a real apprenticeship, although he assures her it won't be easy.
Far from the upbeat Turtle of years past, this Michelangelo has no use for anything other than complete dedication and absolute discipline, promising to push his form of mentorship beyond anything Splinter ever put his own students through. It's already proven to be rough enough, but even after the thrashing she receives at his hands, Casey is overjoyed to take him up on the offer. Not only is it a heartwarming moment inside of an otherwise dreary series, it's also the most important undertaking that Michelangelo has ever thrown himself into.
Casey isn't just his friend's daughter, nor is she just another operative for the resistance effort. She is the only heir to everything that her parents and the Splinter Clan built together. There might not be much of it left beyond their subterranean lair and the stacked mobile armory it holds, but that doesn't make it any less important. The young Casey Jones has already decided what road she wants to go down, and with her mother's support plus Mikey's tutelage, it's hard to think she won't be the one leading the charge when she is inevitably passed the Last Ronin's torch. With any luck, that won't be happening any time soon, even if it is nice to think about.