Kaya the Inexorable + Ugin's Nexus + Karn, the Great Creator + Ashnod's Altar

Kaya the Inexorable

Ugin's Nexus

Karn, the Great Creator

Ashnod's Altar

How it works

1. Activate Karn's first loyalty ability by putting a loyalty counter on it, causing Ugin's Nexus to become an artifact creature until end of turn.
2. Activate Kaya's first loyalty ability by putting a loyalty counter on it, putting a ghostform counter on Ugin's Nexus.
3. Activate Ashnod's Altar by sacrificing Ugin's Nexus, adding CC.
4. Ugin's Nexus is exiled instead of being put into your graveyard, causing you to take an extra turn after this one.
5. Ugin's Nexus triggers, returning itself from exile to your hand, and creating a 1/1 Spirit creature token.
6. Move to your next turn.
7. Activate Ashnod's Altar by sacrificing the Spirit token, adding CC.
8. Cast Ugin's Nexus by paying 5.
9. Repeat.