This clever loop turns the graveyard into a reliable supply depot by leveraging Leonardo, Sewer Samurai's ability to let you recast creatures with power or toughness 1 or less from your graveyard. Normally, the finality counter tacked onto that cast would permanently exile the creature upon death, but Solemnity acts as an absolute shield, preventing any counters from ever being placed on your permanents. This allows Memnite to return to the battlefield completely unburdened time and time again. Meanwhile, Arcbound Ravager sits ready to sacrifice that same Memnite on command, accumulating a growing pile of +1/+1 counters and fueling an endless cascade of sacrifice and death triggers.