Um, okay, thought I'd give this a shot...
Name: Eddie Riggs
Series of Origin: Brütal Legend
Pony Breed: Tough to pick, as he can fly and use magic in his game of origin. But the wings won out (his powers could be explained as part of his Cutie Mark talent, heh). Pegasus.
Appearance, Pre-Pony: Right here.◊
Appearance, Pony: Oh I wish I had a picture. Anyway, he'd be a larger pony, think Big Mac Intosh
-sized. Black coat, black mane and tail with red streaks, brownish-red eyes. Probably demonic wings, like the pegasi that Princess Luna had, black with red membranes between the finger structure. Likely wearing spiked bands on his legs and an open leather vest. Cutie mark would be his axe and guitar crossed, in flames.
Personality: Paraphrasing the wiki. "Eddie's personality can be immature at times, and he is almost always sarcastic and snarky. However, he also knows when it's time to be serious, and is an efficient and capable leader of men. He also knows that, as a roadie, his place isn't in the leadership of an army, but more in behind-the-scenes work. Eddie is also friendly and a good advisor, when people have doubts of what they can do, Eddie supports them and helps them realize how strong and powerful they really are. Eddie also has a strong sense of justice in him when someone is being attacked or discriminated, like when Doviculus killed both Lars and Ophelia, Eddie would stop at nothing to defeat him and avenge his friends." For all his good traits, though, Eddie isn't perfect, as he will not tolerate being disrespected and reacts poorly when secrets are kept from him. (Note...try to keep him away from Pinkie Pie.)
Abilities and Equipment: Eddie was already able to fly and use lightning powers in his game, which most pegasus ponies can, and is unnaturally strong, able to easily carry most of a car body or to lift giant speakers in one hand...all of this due to his half-demon nature. He also wields Clementine, a Flying V guitar, with which he can attack with fire, and a giant battle axe. He'd probably have some trouble with these in pony form, but would probably figure out a way to to make them work at least somewhat. Also skilled in building/repairing most anything, organization, and other things so far as "putting a band together and taking it on the road". His special talent would probably be best described as "Roadie-ing." His guitar also has the ability to perform certain spells, but all have long recharges and can only be used occasionally, plus several of them would be redundant in the presence of other ponies (who needs "Call Of The Wild" when Fluttershy's around?) along with what would probably be extreme difficulty in casting with pony hooves. He's a competent if unorthodox fighter, but is ultimately better at supporting others rather than taking front and center himself.