2017-09-29
Storm Sculptor's last ability doesn't target the creature you'll return to hand. You choose one as the ability resolves. No player may take actions between the time you choose a creature to return and the time you do so.
2017-09-29
Storm Sculptor's last ability isn't optional. If Storm Sculptor is the only creature you control when the ability resolves, you'll have to return it to its owner's hand.