James, Rebel Leader

Whenever a creature enters the battlefield under
your control, you may give it haste. If you do,
return it to its owner's hand at the beginning of
the next end step.
If a creature with haste that you control has dealt combat damage to a player this turn, you may pay {w}{u}{r} rather than pay the mana cost of the next instant or sorcery you cast. If you cast a spell this
way, that spell gains rebound.