Activate Mystic Sanctuary and Lavabrink Floodgates by tapping them, adding 2.
Cast Ghostly Flicker either from your hand or from the top of your library by paying 2, blinking Mystic Sanctuary and Lavabrink Floodgates.
When Mystic Sanctuary enters untapped, it triggers, putting Ghostly Flicker from your graveyard onto the top of your library.
Repeat.
This cunning loop turns the top of your library into an engine of endless iteration by repeatedly blinking your lands with Ghostly Flicker. As Mystic Sanctuary enters the battlefield untapped, its triggered ability swoops in to rescue Ghostly Flicker from your graveyard and place it right back on top of your library, perfectly positioned for One with the Multiverse to cast it again without paying its mana cost. Meanwhile, Lavabrink Floodgates acts as your primary mana source to power the spell, while its passive doom counter mechanic ticks away in the background without interrupting your infinite cycle.