This clever loop transforms simple life payments into an avalanche of resources by exploiting the recursive synergy between Vilis, Broker of Blood and Sheoldred, the Apocalypse. When you pay 1 life to activate Carrion Howler's ability, Vilis triggers from the life loss to hand you a card, which in turn causes Sheoldred to trigger and restore more than enough life to keep the engine going indefinitely. Because Vilis converts every single point of lost life into fresh cards while Sheoldred pads your total with a net gain on every draw, you can cycle this sequence as many times as you desire to sculpt the ultimate hand and amass a massive life total.