Has it stopped being terrible? I'll probably stop hating on it when it stops being terrible.
Pretty much.
1. What on earth is with it's hands and feet? It has like toes for feet and it's fingers are incapable of grasping anything now. It looks like someone made some dwarfed version of Mewtwo with play-doh.
2. Why on earth is that band on it's head? It looks ridiculous, and even weirder that it connects to it's horn ears. The designers at gamefreak just put stuff on just to put stuff on now (aka Moevee). I'll tell you why they put that headband on, though, to hide how ugly it's head is if it didn't have it.
3. What is the point of the chest spikes? It's like Gardevoir x2, except less colorful and no sense. What is he going to stab them with his stomach? "UGH! UGH! Take this! UGH!"
4. Why on earth is it's tail on it's head?
5. The existence of this thing is so idiotic that it makes absolute zero sense to any possible storyline they could concoct. From 5 whole Generations of a standard Mewtwo, with 2 Mewtwo movies and everything being explained about it without any plotholes, they are adding a new form just to say they added a new form.
Simply put: It looks dumb, the idea behind it is dumb, and whoever thought this was great is getting their just desserts from all the people who hate it.