Blind Ante
I had a recent request from a player to have a hidden talent of their character. The player wanted to give the character a sense that they were special in some way, but their true nature is unknown. It reminded me of a few years ago when I was playing around with destiny. I liked that experience for myself and I thanked my player for giving me some creative freedom over his character. Quite a privilege.
This doesn't break any rules, other players can impact a way a character fleshes out. So to can the narrator, or even the enemies of a game. Still, to decide secretly what magical qualities the PC has will be a lot of fun. Believe me I immediately had idea, seconds after I was imbued with the power.
I'm excited for this and I'm offering it up as a suggestion even though I haven't tried it yet. Allowing your fellow players the detailing about your character could be a very creative opportunity.
Be careful of course. Wouldn't want to find our you have only one arm when you begin play. Stick with the idea above, something nobody (in the game) would know. Only the Narrator (and destiny) will reveal the truth.
Or be bold and go in without any knowledge. Simply assume the role you have been dealt!
A wild time indeed!