Activate Mystic Sanctuary and Stonespeaker Crystal by tapping them, adding CC.
Cast Ghostly Flicker either from your hand or from the top of your library by paying 2, blinking Mystic Sanctuary and Stonespeaker Crystal.
When Mystic Sanctuary enters untapped, it triggers, putting Ghostly Flicker from your graveyard onto the top of your library.
Repeat.
This clever loop lets you recast Ghostly Flicker indefinitely by continually rebuying it from the graveyard with Mystic Sanctuary. Madame Web, Clairvoyant is the crucial enabler here, granting you the ability to cast noncreature spells straight from the top of your library while also helping you dig through your deck. Meanwhile, Stonespeaker Crystal provides the mana needed to keep paying for the spell's cost every iteration. By constantly blinking both the land and the artifact, you generate an endless storm of triggers and effects without ever running out of resources.