Ugin's Nexus + Esoteric Duplicator + Atog

Ugin's Nexus

Esoteric Duplicator

Atog

How it works

1. During your end step, activate Atog by sacrificing Ugin's Nexus.
2. Ugin's Nexus is exiled instead of being put into your graveyard, causing you to take an extra turn after this one.
3. Esoteric Duplicator triggers, causing you to pay 2 to create a token copy of Ugin's Nexus at the beginning of your next end step.
4. Resolve the Atog ability, giving it +2/+2 until end of turn.
5. Move to your extra turn.
6. At the beginning of your end step, Esoteric Duplicator triggers, creating a token copy of Ugin's Nexus.
7. Repeat.

This clever loop hinges on the unique replacement effect of Ugin's Nexus, which grants you an extra turn whenever it goes to the graveyard—an outcome we neatly bypass by exiling it instead, successfully dodging its restriction against actually taking those extra turns. By feeding Ugin's Nexus to Atog, you immediately trigger Esoteric Duplicator, allowing you to pay `{2}` to set up a cloned copy of the artifact for your upcoming end step. Because you loop this process each turn, you continuously generate fresh Ugin's Nexus tokens to sacrifice while chaining an endless sequence of extra turns.