This is amazing! Although I agree that Alternate animations are a bit stiff, also I think you forgot to add attack sounds to when he swings his blades.The collision shapes don't have coordinates because of that they are placed like this (picture 1). Alternate form lacks hand and feet attachments.
Again, the model's is great, I'm just trying to give feedback.
P.S. I don't know if it's too much to ask, but I wish he had a flight anim in demon form named "Walk Fast"