Daretti, Ingenious Iconoclast

Oracle Text

+1: Create a 1/1 colorless Construct artifact creature token with defender.

−1: You may sacrifice an artifact. If you do, destroy target artifact or creature.

−6: Choose target artifact card in a graveyard or artifact on the battlefield. Create three tokens that are copies of it.

Card Rulings

8/23/2016 For the second ability, you choose the target artifact or creature as you activate the ability. You choose whether to sacrifice an artifact and which artifact to sacrifice as the ability resolves.
8/23/2016 For the last ability, if you choose an artifact on the battlefield as the target, and that artifact is no longer on the battlefield as the ability tries to resolve, the ability won’t resolve and none of its effects will happen. You won’t get any tokens. This is true even if the card that represented that artifact is now in a graveyard. That card will be a different object than it was on the battlefield.