25 parts Complete Mature(Megatron OC X RWBY/MHA/Kuroinu/Taimanin)
Xander Jacobson was a student of U. B. A. High (U. A. High + Beacon Academy), who made a few friends during his journey to become a true hero. But then he overheard a conversation between the headmasters and his team Leader Victor Adam discussing about starting a breeding program between their female members and the creation of half Grimm/half Nomu creatures they've found during a raid on a villain base.
Realizing the dangers, he gathers a small group of students and staff (Class 1-B, Eraserhead, Ms. Joke, Midnight, Mirko, Ryukyuu, Team CFVY, Glynda, Team RWBY and Team JNPR), and informs them of what he heard and how he plans to contact two childhood friends of his & asking for him to join them.
Unfortunately, Victor stops them and engages Xander in a combat which ends with Victor winning and scarring his left eye. As Victor was about to kill Xander, his friends Kohaku and Sakura save him and take him somewhere else, where he becomes the reincarnation of the leader of the Decepticons himself. Now Xander is ready for payback.