Story/plot wise, nothing I'm immediately thinking of...

Character wise, I'm thinking of playing a character I had in a Zelda game somewhere else, but the game died pretty fast, so I didn't have the chance to really play him much....

In a nutshell: Majora's Mask. He makes masks and they grant him different forms. 

He's an artist who travels around, putting a lot of time, dedication, and research into his masks. He can't just throw one together and slap it on. He immerses himself in the culture or the life of his subject (depending on if it's a race or animal) and gathers materials carefully. (In dark Majora's Mask fashion, they often involve real body parts- typically, he prefers to adorn skulls, but for animals, he may tan a hide.)

Would that be an acceptable ability? The way the ~magic~ of it works, they only work for him.