Morkus from Orkus
None of those. He's literally a full celestial with additional magical ability, including learned magic from other races.except if your concept isn't the class features normally you can make them multi ways...
Is Gandalf an Aasimar Wizard, or a Varriant Human Bard, or a custum linage divine soul sorcerer?
D&D can't model him via PC classes. From the books we know he is a full celestial, learns magic from other races like D&D Wizards, but doesn't study magic from books or prepare spells daily and casts more like an unlimited Sorcerer. You'd have to create a special NPC stat block for him and abilities.
Again, none of those. He's more than human, since he has small strains of celestial blood and elven blood that give him special abilities, but not enough elven blood to be half-elven or enough celestial blood to be a deva.Is Aragon a human ranger, a half elf fighter/rogue, a deva warlord?
He'd also need a special NPC block to cover what he is.