Tezzeret, Servant of Bolas

Menace, Intimidate
Whenever Tezzeret deals combat damage to a player, draw that many cards.
{1}{u}{t}: Draw a card
Whenever an artifact enters the battlefield under your control, {ut} Tezzeret.
At the beginning of each end step, if you drew five or more cards this turn, you may exile Tezzeret, then replace him with Tezzeret, Master Artificer.