Making a Mystery Character

If one of your players just cannot come up with a character concept they like, there is the option of asking them to play a mystery character. This will be an ordinary, simple character, but the player knows there is something about this character that no one (not even themself) knows. There is just something mysterious that will become apparent as the game proceeds. Troubling dreams, strange memories, sudden, unexpected powers, these are all possibilities. The reason this works is because the character doesn't know they have these powers, just as the player doesn't. As the player learns everything, so too does the character.

This also lets the player flavour the character however they see fit, which may or not contrast wildly with what the character's eventual secret is. Simon of Space is a good example; his old self is a ferocious, tyrannical leader, while Simon is meek and humble and easygoing...BUT has the hidden "power" of name recognition, being rich, and connections that he stumbles upon.