Ones you have used, ones you are using, or ones you just have.
Human "Barbarian" Paladin of Bahamut:
Basically saw a dragon once and become obsessed with how strong they were and fell assbackwards into worshiping Bahamut.
Elderly Tiefling Wizard:
Up for anything, basically doesn't give a shit anymore, just wants to do illusion magic and parlour tricks and maybe help a few people if they can.
AMAB Enby Devil-Cleric:
Self-serving, sugardaddy is Asmodeus, or some other devil, they made a pact with in exchange for hrt and magic powers.
I'd probably make some kind of dwarf warrior who was a miner in a former life but his family was killed when the mining guild dug too deep and awoke an ancient beast, now he lives to take revenge on said creature. Kind of like a Captain Ahab type, with an eye patch who wields a lance larger than himself because of how powerful he is.
based
I'd imagine he'd grow as a character and learn to let go of revenge and become involved with the struggle of the common people while living his new life as a professional adventurer/mercenary. His arc would be complete when he fights in a successful peasant uprising to overthrow the monarchy.