This elegant loop turns the graveyard into a recursive engine by leveraging the zero-mana artifact creature Memnite as the ultimate expendable fuel source. Once you feed Memnite to Ashnod's Altar to generate colorless mana, Havengul Lich steps in with its activated ability, allowing you to continually recast that same Memnite straight from your graveyard for free. Because the Lich's activation cost is easily fueled by the mana from the Altar, you can cycle this sequence endlessly to generate infinite colorless mana alongside an infinite stream of enter-the-battlefield, leave-the-battlefield, death, and sacrifice triggers.