So many choices, but my top choice is Human (Mulhorandi) Divine Sorceror (good or chaotic) descendant of Shares (Bast), whose was badly wounded by dark Imaskari curse, with the lingering effect sops his strength, to the point that only the divine magic flowing through him keeps him alive at all, but with the side effect that he is always in a state of divine rapture (basically drugged out on divine energy).
My second choice is Shadow Sorceror Drow, the result of two drow nobles experimenting with breeding while possessed by shadow demons (consentually, it was research between drow wizards). Drow High Magic feat.
A Horizon Walker Half Elf that draws his power from the plane/domain of Brightwater, the afterlife of Sune, Llira, and Sharess.
A Druid of the Shepherd that worships Lurue, who creates creatures and fey spirits, by shaping the raw magic primal energies of the feywild and the elemental chaos. Will have ritual caster (wizard) for the familiar spell.
College of Whispers Bard, a Tiefling whose infernal heritage tainted his bardic music by accident.
A Tiefling Divine Soul (Evil or Lawful) of Lovitar, always keeps his word to allies, but enjoys being cruel to his enemies. Sadistist, but smart enough to leave his allies alone. Likes summoning fiends and fiendish spirits. Maybe a level of Barbarian.