(play Swamp as land drop, cast Dark Ritual, use floating mana for Altar of the Brood Heartless Summoning, Myr Retriever cast for no mana - it dies, 2nd Myr Retriever also for zero mana - it dies and brings the other Myr Retriever back to your hand and begins the loop as the opponent is milling a card each time, and you keep milling them a card at a time as the loop happens and they simply mill out on the first turn)
It is fragile and you have to get the combo in the first couple turns, but you can mull to six to have second shot at it.
Legacy legal
