Toph, the First Metalbender + Ugin's Nexus + Zuran Orb + Meticulous Excavation

Toph, the First Metalbender

Ugin's Nexus

Zuran Orb

Meticulous Excavation

How it works

1. Cast Ugin's Nexus by paying 5.
2. At the beginning of your end step, Toph triggers, causing Ugin's Nexus to become an artifact land creature.
3. Activate Zuran Orb by sacrificing Ugin's Nexus. Ugin's Nexus is exiled instead of being put into your graveyard, causing you to take an extra turn after this one.
4. Toph triggers, returning Ugin's Nexus from exile to the battlefield.
5. Resolve the Zuran Orb ability.
6. Activate Meticulous Excavation by paying 2, returning Ugin's Nexus from the battlefield to your hand.
7. Repeat each turn.

By transforming your nontoken artifacts into lands, Toph, the First Metalbender turns Ugin's Nexus from a mere turn-stealer into a legal sacrifice target for Zuran Orb. When you sacrifice Ugin's Nexus to the Orb, its replacement effect snatches an extra turn from the ether and exiles itself instead of hitting the graveyard, sidestepping its usual finality. From there, Toph's earthbend ability or a timely activation of Meticulous Excavation ensures Ugin's Nexus loops right back to your hand or battlefield so you can chain infinite turns indefinitely.