This is my first time making a character and I had the idea to have her sprout angel like wings of light from her back to fly. So that would be the flight power with the wings flaw but she doesn't have the wings all the time. She just turns them on and off when she needs them.
So my question is, what is the best way to go about her wings activating and deactivating? I'm not sure what kind of power that would use.