With the main 'bad guy' being good initially I want him to give off a weird, I don't trust you feel. To try and portray this I want to give him creepy features so even if he was a 'good guy' you still wouldn't totally trust him.

 A common occurrence in sorcerers seems to be hoods, big shoulder pads and long coats. however, though these guys look a little untrustworthy, this guy is a  powerful sorcerer he would transform himself to be a little better suited to his surroundings. With the temple being in the middle of nature, I think it would be cool if he was centaur or something.

I like the idea of the bottom half of him to be spider or crab or anything that scurries because i know a lot of people, including my self, get freaked out by things like that so I think that something like that will give the desired off putting look i am looking for.

I have found quite a lot of examples of half horse but i am struggling to find much of anything else, I am going to do a few animation tests of a spider walking to give myself a clearer view of what it is i want him to look like.