Dack, King of Thieves

When Dack, King of Thieves enters the battlefield, gain control of target artifact with converted mana cost 3 or less.
Sarcrifice an artifact: Put X Gold counters on Dack, where X is the converted mana cost of the sacrificed artifact.
{u}{r},{t}, remove X gold counters from Dack: Gain control of target nonland permanent with converted mana cost X.