Daell, the Enduring

When Daell, the Enduring enters the battlefield and at the beginning of your upkeep, you may exile a creature card from your graveyard. If you do, create a 1/1 white Spirit creature token with flying.
Whenever you attack, you may put a creature card you own in exile onto the battlefield tapped and attacking if it has power less than or equal to the number of attacking crea