Activate Mystic Sanctuary and Sceptre of Eternal Glory by tapping them, adding 3
Cast Ghostly Flicker either from your hand or from the top of your library by paying 2, blinking Mystic Sanctuary and Sceptre of Eternal Glory.
When Mystic Sanctuary enters untapped, it triggers, putting Ghostly Flicker from your graveyard onto the top of your library.
Repeat.
This clever loop relies on Future Sight to let you play spells directly from the top of your library, making it the workshop where the entire engine runs. You cast Ghostly Flicker targeting Sceptre of Eternal Glory and Mystic Sanctuary, which refills your mana and triggers the land's ability to place Ghostly Flicker right back on top of your library. Sceptre of Eternal Glory is the true engine of this machinery, tapping for three mana to comfortably pay for Ghostly Flicker's casting cost each iteration, while Mystic Sanctuary acts as the recursive glue that recycles your spell endlessly.