Emry, Lurker of the Loch + Displacer Kitten + Welding Jar + Derevi, Empyrial Tactician

Emry, Lurker of the Loch

Displacer Kitten

Welding Jar

Derevi, Empyrial Tactician

How it works

1. Activate Emry by tapping it, targeting Welding Jar.
2. Cast Welding Jar from your graveyard by paying 0.
3. Displacer Kitten triggers, blinking Derevi.
4. When Derevi enters, it triggers, untapping Emry.
5. Activate Welding Jar by sacrificing it.
6. Repeat.

This intricate loop transforms the lowly Welding Jar into a perpetual motion machine by leveraging Emry, Lurker of the Loch to recast it from the graveyard at no mana cost. Every time you cast that artifact, Displacer Kitten triggers its avoidance ability to blink Derevi, Empyrial Tactician, resetting the battlefield. When Derevi enters, its triggered ability untaps Emry so you can tap her to repeat the process all over again.