This loop relies on transforming Enduring Vitality into a creature using Zur, Eternal Schemer so it can tap for mana via its own granted ability and be fed directly into Ashnod's Altar for colorless mana. Mass Hysteria ensures that when Enduring Vitality's own death trigger returns it to the battlefield as an enchantment, Zur can immediately animate it again without waiting around for summoning sickness. Because Enduring Vitality is inherently equipped with a self-resurrection clause whenever it dies as a creature, you can repeat this cycle endlessly to generate infinite sacrifices, leaves-the-battlefield triggers, deaths, and a massive surplus of colorless mana.