Arcbound Reclaimer + Showdown of the Skalds + Elsha of the Infinite + Welding Jar

Arcbound Reclaimer

Showdown of the Skalds

Elsha of the Infinite

Welding Jar

How it works

1. Cast Welding Jar either from your hand or from the top of your library by paying 0
2. Showdown of the Skalds and Elsha's prowess ability trigger.
3. Resolve the Showdown of the Skalds trigger, putting a +1/+1 counter on Arcbound Reclaimer.
4. Resolve the Elsha trigger, giving it +1/+1 until end of turn.
5. Activate Welding Jar by sacrificing it.
6. Activate Arcbound Reclaimer by removing a +1/+1 counter from it, putting Welding Jar from your graveyard onto the top of your library.
7. Repeat.

This brilliant loop sets up an endless engine by leveraging Elsha of the Infinite, which allows you to continually cast Welding Jar straight from the top of your library. Each time you cast that artifact, Showdown of the Skalds triggers its second and third lore chapters to place a +1/+1 counter onto Arcbound Reclaimer, fueling the Reclaimer's activated ability to constantly recycle Welding Jar right back to the library's peak. Meanwhile, Elsha's prowess keyword capitalizes on every single iteration to pump up your creatures into massively oversized threats until the end of the turn.