Oltec Matterweaver triggers, creating a copy of a Treasure or Gold token you control.
When Acererak the Archlich enters the battlefield, its first ability triggers, returning it from the battlefield to your hand, and venturing into Lost Mine of Phandelver.
Activate a Treasure token by tapping and sacrificing it, or a Gold token by sacrificing it, adding .
Repeat.
This wicked loop turns the dreaded lich Acererak the Archlich into an endlessly repeating dungeon expedition, made possible because Heartless Summoning slashes his casting cost down to a single black mana. Each time you replay him, Oltec Matterweaver triggers to duplicate your existing mana-producing artifact tokens, funding the next cast while fueling an infinite storm count and endless dungeon progress. Because Acererak's own enter-the-battlefield ability immediately bounces him back to your hand whenever you venture into any dungeon *except* the Tomb of Annihilation, you can endlessly repeat the process to squeeze infinite value out of Lost Mine of Phandelver.