Turnabout + Ghostly Flicker + Ardent Elementalist + Scrivener

Turnabout

Ghostly Flicker

Ardent Elementalist

Scrivener

How it works

1. Activate any number of lands you control by tapping them, adding at least 4.
2. Cast Turnabout by paying 2, untapping all lands you control.
3. Cast Ghostly Flicker by paying 2, blinking Ardent Elementalist and Scrivener.
4. When Ardent Elementalist and Scrivener enter the battlefield, they trigger, returning Turnabout and Ghostly Flicker from your graveyard to your hand.
5. Repeat.

This engine transforms a modest pool of mana into an endless loop by cycling your spells through the graveyard and right back to your hand. You kick things off by tapping your lands to pay for Turnabout, which deftly untaps them to leave you with a surplus of mana. From there, Ghostly Flicker comes down to exile both Ardent Elementalist and Scrivener simultaneously, blinking them away and immediately returning them to the battlefield. The moment Ardent Elementalist enters, its triggered ability plucks Turnabout back from your graveyard, while Scrivener's triggered ability handily retrieves Ghostly Flicker. Because these recursion pieces catch everything you just cast, you can repeat the entire sequence to generate infinite mana, storm count, and endless entry triggers.