[x] The Sin of Gluttony: Transformed into an abomination as the result of a horrible experiment you are the eldest and most powerful of your brother answering only to the Lady of Sin in your forces proverbial hierarchy, and that's saying something considering how strong each and every one of your siblings are.
Pros: You could easily be an Big bad in your own right if you weren't working with seven beings who all shared the same weight class.
Cons: You are a major 'Knight of Cerberus' even the other forces of evil are afraid of you so expect them to start ramping very quickly if you show up in your true form, or your power becomes to prevalent.
[x] Beautiful Fairy Princess!: Descended from a line of good fey the Fairy Princess attacks her enemies using a variety of confusing magical attacks.
Tricks and prestidigitation vs sheer raw whatever-we-wield? Nice.
Edit: also, I like the premise. I really do, and I don't want it to dissolve. The mad experiment and the werewolf smell to me like independant actors, too much risk of the quest turning neutral within the first 10 turns. The homunculus option is too close of grey vs gray to me. This option ensures the main theme keeps existing, that the main conflict does not mutate into "I'm bad, but not really. I'm just a helpful neutral party".