Ugin's Nexus + Esoteric Duplicator + Atog

Steps

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.