Saheeli, Sublime Artificer + Mirror of Fate + Contagion Engine + Alrund's Epiphany

Saheeli, Sublime Artificer

Mirror of Fate

Contagion Engine

Alrund's Epiphany

How it works

1. Cast Alrund's Epiphany by paying 5.
2. Saheeli triggers, creating a 1/1 Servo artifact creature token.
3. Resolve Alrund's Epiphany, causing you to take an extra turn after this one and exile it.
4. Activate Contagion Engine by paying 6 and tapping it, putting two loyalty counters on Saheeli.
5. Activate Saheeli by removing two loyalty counters from it, causing the Servo to become a copy of Mirror of Fate until end of turn.
6. Activate the Servo by tapping and sacrificing it, choosing Alrund's Epiphany and up to six other cards face up in exile, then exiling your library and putting the chosen cards on top of your library, with Alrund's Epiphany being the top most card.
7. Move to your next turn, drawing Alrund's Epiphany during your draw step.
8. Repeat.

This intricate loop achieves infinite turns by continuously recycling a single copy of Alrund's Epiphany right back to the top of your library. Saheeli, Sublime Artificer provides the crucial engine fuel: every time you cast your extra turn spell, she generates a 1/1 Servo artifact creature token. When Contagion Engine's heavy activation cost pumps Saheeli's loyalty back up, she can use her minus ability to turn that Servo into a temporary copy of Mirror of Fate. Sacrificing that copied mirror then lets you sweep through your exile zone, stacking Alrund's Epiphany as the very next card you will draw to repeat the cycle indefinitely.