Saheeli, Radiant Creator + Karn, the Great Creator + Ugin's Nexus + Lae'zel, Vlaakith's Champion + Izzet Generatorium

Saheeli, Radiant Creator

Karn, the Great Creator

Ugin's Nexus

Lae'zel, Vlaakith's Champion

Izzet Generatorium

How it works

1. Cast Ugin's Nexus by paying 5.
2. Saheeli's first ability triggers, causing you to get EEE.
3. At the beginning of your combat phase, Saheeli's second ability triggers, causing you to pay EEE to create a token copy of Ugin's Nexus that is a 5/5 artifact creature.
4. Put the nontoken Ugin's Nexus into exile due to the legend rule and its replacement effect, causing you to take an extra turn after this one.
5. Activate Karn's first loyalty ability by putting two loyalty counters on it.
6. At the beginning of the end step, Saheeli triggers, causing you to sacrifice the Ugin's Nexus token. The token put into exile due to its replacement effect, causing you to take an extra turn after this one.
7. Move to your first extra turn.
8. Activate Karn's second loyalty ability ability by removing two loyalty counters from it, putting Ugin's Nexus into your hand from exile.
9. Move to your second extra turn, and repeat from step 1.