As far as looks go he's one of those split down the middle dealies. One angel wing one demon wing. One red eye one blue. One tiny horn and a small halo off set to the side. Black hair on one side white hair on the other. One hand has black demon claws and the other has retractable cat like claws. He has nice shiny teeth with sharp canines. He wears a button down shirt the right half is blue with white stars and the left half is black with red designs. His pants are long and white on one side and black on the other.
Personality wise he is a pretty normal teenage elf guy. But that's just him. There's also
Him and
Him...
When his parents experimented with the celestial and fiendish seed spells, the outcome was that he was born with a personality for each heritage.
The cruel and angry Fiend. The overly nice and goody goody Celestial. And the actual person who the other two fight for control over.
The angel is a cleric of "The Host" (anything celestial) because it knows it should be one of them.
The Fiend is a wizard, studying the arcane ways of it's abyssal namesake, trying to gain the power it should have.
His goal at Avalon is to gain control over the other two and use them and their abilities in harmony. He can't use any of his abilities without either persona having control. And he only gets half for each.
The angel gets Cleric and Gunslinger.
The fiend gets Wizard and Fighter.
His magic items are a half and half looking shirt that changes into Demon Armour or Robe of Stars depending on persona. (You can guess which.)
And a switchblade that becomes a Called Fighter's Fork or a Pistol of the Infinite Sky.
(Persona Dependant)
It's a switchblade for him because I couldn't think of anything better.
The wizard is an infernal binder and the cleric has the law and good domains.