Zero is a duplicate of Lockley created from his shadow.
For a while after his accidental creation he spent the majority of his time antagonising Lockley. He has since settled down and commonly associates with Seran, a resident of Atheria.
Zero uses numbered techniques. These numbers relate to the number of attempts taken to perfect the technique. For example, Firestorm 329 took 329 attempts before Zero could perform it to his liking.