Dragon Priest Avatar by sulmith greysin

dragonpriestavatar.esp should be in skyrim's data folder in the install directory

the spell tome is sold by Lucan at the Riverwood Trader

KNOWN PROBLEMS:

buggy AI like all followers have, you can simply resummon or bump into him. it's not
any worse than the default follower AI

in tight, multi-level buildings/helgen keep where there are multiple
enemies in a small area, he may detect them through walls if they're
in combat and try to attack before you actually get to them.
this is also related to the default ai behavior of npcs

to add your own custom skin, the file you want to edit is inside the optional 
texture pack as dragonpriestdefault.dds. open that with gimp or photoshop
and simply edit then place in the data\textures\actors\dragon priest folder
in your directory

project will be constantly updated