Activate Mystic Sanctuary and The Great Henge by tapping them, adding and causing you to gain 2 life.
Cast Ghostly Flicker either from your hand or from the top of your library by paying 2, blinking Mystic Sanctuary and The Great Henge.
When Mystic Sanctuary enters untapped, it triggers, putting Ghostly Flicker from your graveyard onto the top of your library.
Repeat.
This delightful loop relies on Mystic Sanctuary entering the battlefield untapped via Ghostly Flicker, triggering its ability to place the very same Ghostly Flicker back on top of your library. From there, One with the Multiverse allows you to play that freshly-decked instant right off the top of your library, while The Great Henge pitches in the green mana needed to pay for the spell's casting cost while padding your life total along the way. Every iteration resets the land and the artifact to churn out endless value, beautifully bridging lands, artifacts, and spells into an unstoppable cycle.