I don't know much about him. What it seems like it should involve is disabling any despawn, so he doesn't disappear after the quest, and giving him the current and potential follower faction ranks, then having the successful deal alter his disposition toward you. I'm not sure if that would require a new relationship or not. Unfortunately, it will involve quest work, which is far beyond my skill.
As far as creating a new follower, here are the tutorials I used. I like videos for clarity, but I like these because I can keep them in the background and keep referring to them, step by step.
You might try right-clicking on him and duplicating him, see if that will let you create a doppelganger of him to use as a follower. If not, you should be able to create a new actor, open his actor form up next to it, and match the details to make an identical non-copy.
Some things you may run into:
Wrong relationship setting - I don't know if "lover" is actually required, as the tutorial says, or if you can get away with friend, ally, etc. I followed verbatim, and the few followers I've made do work with that setting.
Wrong faction ranks - I'm not in a position to get into CK and check, but I believe the right factions are potential follower = 0 and current follower = -1. Double check that with the tutorials, or open vanilla follower and double check theirs. Wrong ranks and they won't follow you.
Wrong voice type - I don't know of a Dremora follower, so you may have to change voice in order to get it to work. Only some voices will allow the "follow me, I need your help" dialog to even appear. I have a petite little khajiit lady running around, with a female orc voice, for that reason. She looks like a proper lady, but sounds like she did 20 yrs of factory work, after she got out of the navy. Best bet is to try the same voice as vanilla, but if you don't get the dialog, switch it to a voice you know works and test again. Open up Faendal or someone, and match voice types.
Hope it helps.