Dack, Notorious Thief

Flash
When Dack, Notorious Thief enters the battlefield, gain control of target artifact for
as long as Dack remains on the battlefield.
As long as you control a permanent you don't own, Dack gets +2/+0 and has "{2}, Discard
two cards: Draw two cards."
"Name's Dack. I'm sure you've heard it."