NRG, Prypiatosian-B Unarmored

Flying, indestructible
Whenever you cast a spell that inflicts
damage to a creature or player, you may inflict an additional four damage and this creature gains a +1/+1.
Return an artifact to your hand: Exile NRG, Prypiatosian-B Unarmored and return it to
the battlefield transformed under his owner's control.