Vorel of the Hull Clade + Ichormoon Gauntlet + Liquimetal Torque + Karn Liberated

Vorel of the Hull Clade

Ichormoon Gauntlet

Liquimetal Torque

Karn Liberated

How it works

1. Activate Liquimetal Torque's second ability by tapping it, causing Karn Liberated to become an artifact until end of turn.
2. Activate Vorel of the Hull Clade by paying and tapping it, doubling the number of counters on Karn Liberated.
3. Activate Karn Liberated by removing twelve loyalty counters from it, causing you to take an extra turn after this one.
4. Repeat each turn.

This loop uses Liquimetal Torque to turn Karn Liberated into an artifact, which is the crucial trick that allows Vorel of the Hull Clade to double the planeswalker's loyalty counters instead of just restricting itself to creatures, lands, or normal artifacts. With Karn's loyalty rapidly multiplying beyond his starting total, you can safely activate his ultimate ability to take an extra turn. Meanwhile, Ichormoon Gauntlet quietly supports the engine in the background: its passive ability grants Karn a zero-cost Proliferate option to help nudge his counters upward, while casting your noncreature spells triggers its second ability to continuously add fuel to the fire.