Ugin's Nexus + Aetheric Amplifier + Karn, the Great Creator + Krark-Clan Ironworks

Prerequisites

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Steps

1. 1If Karn has exactly one loyalty counter on it, activate its first loyalty ability by putting a loyalty counter on it.
2. 2Activate Krark-Clan Ironworks by sacrificing Ugin's Nexus. Ugin's Nexus will be exiled instead of being put into your graveyard due to its replacement effect, causing you to take an extra turn after this one.
3. 3Move to your next turn.
4. 4Activate Aetheric Amplifier by paying and tapping it, doubling the number of counters on Karn.
5. 5Activate Karn's second loyalty ability by removing two loyalty counters from it, returning Ugin's Nexus from exile to your hand.
6. 6Cast Ugin's Nexus by paying .
7. 7Repeat from step 2.

Effects

• Infinite turns
• Lock