anything other then the seer bloodline that could be given to a sorcerer who dosent have any special or magical ancestry, and was kind of just born with magic as a spontainius fluke?
Any of them. You don't have to have an ancestor who got busy with a dragon or an aberrant to have the draconic or aberrant 'bloodline.'
Perhaps grandpa was attacked by a Chaos Beast (or enslimed and dominated by an Aboleth), and barely survived, but now carries some lingering effect from that encounter, that has passed on to affect you.
Maybe your mother was pregnant with you when she was infected with Ghoul Fever, and she survived, but you remain touched with an affinity for the undead.
Uncle Fester spent two decade lost to the world, after disturbing a faerie moot. When he returned, as young as ever, something of the fey magic that had affected him jumped around wildly and affected some of his blood-kin, even, in your case, someone not descended from him, and now you have a 'Fey Bloodline,' despite having no fey in your bloodline.
You thought they were joking when they said that the foul-tasting leathery stuff they had served you was dragon egg, but since that day, you've felt the draconic presence growing within you, as if the potential life that was taken from that egg has chosen to be born from within your soul.
Your great-grandfather swore his allegience to the fiend Narexius, in exchange for the behind-the-scenes skullduggery that made your family the mechant success that it was, but the price would be paid in blood, the devil promised, and when the debt was due, his family would receive a sign. You were born with a birthmark in the form of the devil's sigil (also worked into the family crest), and your mother remembered the legends, attempting to smuggle you away so that the Pact could not claim you as an agent of the infernal. But you can't run from this destiny, and already the whispers in the night have shown you how to work dark miracles...
Experimentation with the ichor of a fallen quasit has led to it coming to some unwholesome type of life, and before you could slap a platter over the squirming fluid, it crawled up onto your skin and seemed to seep within, leaving behind only an ugly red 'birthmark,' like an old poorly-healed burn. Within you the quasit's unclean remains lurk, and you've learned to tap into this abyssal taint for power.
Blessed in exchange for services rendered, your grandmother, a Paladin of Iomedae, crippled in service against the forces of evil, was given 10 years of life, the terrible doom laid upon her by the Balor Carigidor upon his death held at bay, and told that her children would carry the blessings of heaven. Like your father, you have a gift of celestial sorcery, Iomedae's gift to your heroic grandmother.
