Technically you sacrifice all creatures you control, not just the stolen ones, but if you have a way to reanimate or blink Emrakul, you can just steal some more
In that case, Clever Impersonator enters the battlefield as a 0/0 creature, and it's put into the graveyard immediately (unless something is raising its toughness above 0)
You Cannot Hide from Me Ongoing Scheme (An ongoing scheme remains face up until it's abandoned.) At the beginning of combat on your turn, up to one target creature gets +2/+2 and gains vigilance until end of turn
We might as well replace it with a card which does just that thing at a very nice price, Goblin Welder
Probably not, but it sure hits hard in the early turns, and drawing multiples is fine because theyve likely killed the first one
I think this is one of the most underrated competitive card games out there today