MTG >Combos >Ashnod's Altar +Reassembling Skeleton +Chromatic Orrery +

Requirements: All permanents on the battlefield. Sacrifice Reassembling Skeleton using Ashnod's Altar to add two colorless mana. Chromatic Orrery's static ability allows one colorless mana to be spent as if it were black mana. Use the mana to return Reassembling Skeleton to the battlefield, causing ETB abilities to trigger. Repeat infinitely for infinite ETBs.