This is why that people played pokken tournament because Shadow Mewtwo is the most powerful Pokémon in history.I'm pretty sure that Giovanni created Mewtwo,but not Shadow Mewtwo.Wait a minute,Marshadow created Shadow Mewtwo!!!!!!!No wonder why he's powerful than Mewtwo.I can tell that the spikes on Shadow Mewtwo's shoulders are from Marshadow's flames and his eyes.