This elegant sacrifice loop turns a graveyard into an infinite engine, fueled entirely by the clever overlap of copy effects and leaves-the-battlefield triggers. By utilizing Bartolomé del Presidio as your dedicated sacrifice outlet, you send Body Double straight to the graveyard—where it immediately reinvents itself as a copy of Vesperlark. Because Vesperlark's leaves-the-battlefield ability triggers whenever it departs, the returning creature can once again choose to enter as a copy of Vesperlark, ready to be sacrificed all over again for an endless stream of triggers and counters.