Elesh Norn, Mother of Machines (Borderless Ichor) [Phyrexia: All Will Be One] Tiefling Warlock At the beginning of the

At the beginning of the next end step

Set: Oversize Cards Type: Creature — Beast Rarity: Rare Cost: {3}{B} As long as Guardian Beast is untapped

sacrifice Ball Lightning

Shatterskull Pass is a pretty distant second

Elesh Norn, Mother of Machines (Borderless Ichor) [Phyrexia: All Will Be One] Tiefling Warlock At the beginning of theSet: Phyrexia: All Will Be One Type: Legendary Creature Phyrexian Praetor Rarity: Mythic Cost: {4}{W} Vigilance If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time. Permanents entering the battlefield don't cause abilities of permanents your opponents control to trigger.