Storm Sculptor can't be blocked.
When Storm Sculptor enters the battlefield, return a creature you control to its owner's hand.
9/29/2017 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.
9/29/2017 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.