Okay, I'm starting to get a more solid concept, of a character whose blood is a rather exotic mix of bloodlines, all of which are vying to manifest themselves in him:
--------------------
When Dagorae Maggerin met Aedin Qu'cen, their sorcerous magics spoke to one another. He was a human descended of Tarn Linnorm; she an elf whose family had intertwined its line with that of Shaitan. Each had an affinity for acidic magics that left others often cold toward them; caustic powers frighten many who wish to avoid the scars of them. But together, they found solace. And, eventually, a child.
But where their powers and hearts seemed to be in harmony, the birth of their son made it apparent that their child was not. Caytis came into the world with skin covered in minute scales, scales so fine that most see them only as obsidian-colored skin. This combined with his pale hair have long left him confused with a Drow. That he grew into something of a surly child, often complaining of headaches or odd noises no others could hear, earned him few friends.
Despite the obvious physical expressions of his parents' sorcerous bloodlines, Caytis had a great deal of trouble trying to access the arcane powers within him. It was only with a mixture of mental and physical discipline, of honing his body and mind through rigorous study, that he was finally able to channel a fraction of the magics that came naturally to both his progenitors.
Caytis has spent his life looking for balance, teetering between multiple worlds: human, elf, dragon, genie, mage, warrior. It's a perilous quest to manage them all, but he desperately hopes to succeed.
----------------------
Mechanically, looking at a half-elf magus with the Wyrm Blooded trait, taking a dip into crossblooded sorcerer (Linnorm/Shaitan) at second level. I thought he might be loosely associated with House Knowlern, perhaps working as a mine or house guard, or just a caravan escort, I suppose.