Yep, the final Gym leader: Fuckin' Mewtwo. And damn, Mewtwo got hands lol
Its team is mostly made of the clone mons from the first movie (Charizard, Blastoise, Venusaur, light orb Pikachu and a Scyther) boasting pretty much perfect coverage and I imagine better stats than the vanilla counterparts (for example Venusaur can use hydropump and Scyther has Brave Bird)
There's a somewhat big level disparity which I should deal with (most of my team is level 42 while Mewtwo's team is level 52)