Turner's designed some great mons. There's no reason Golurk is bad but the Regis are good besides muh nostalgia. Trevenant, Naganadel, and Guzzlord are pretty well received too.
You want to talk about edgy teenager shit, Mewtwo is the ultimate edge mon. It's an overpowered edgy clone cat with a tragic backstory that hates humanity and wants to defeat strong trainers and use his army of clones to show how much they're superior to natural born creatures. That sounds like it could be straight out of Final Fantasy. If it were a self insert it would basically be a Mary Sue. Anyone who actually thinks Mewtwo is cool and well written is a textbook autist.