Arcbound Reclaimer + Showdown of the Skalds + Delif's Cone + Mystic Forge

Arcbound Reclaimer

Showdown of the Skalds

Delif's Cone

Mystic Forge

How it works

1. Cast Delif's Cone either from your hand or from the top of your library by paying 0
2. Showdown of the Skalds triggers, putting a +1/+1 counter on Arcbound Reclaimer.
3. Activate Delif's Cone by tapping and sacrificing it.
4. Activate Arcbound Reclaimer by removing a +1/+1 counter from it, putting Delif's Cone from your graveyard onto the top of your library.
5. Repeat.

This loop turns the seemingly humble Delif's Cone into an infinite engine by leveraging Mystic Forge to repeatedly cast it from the top of your library for zero mana. Each time you cast the artifact, chapters II and III of Showdown of the Skalds trigger to replenish a +1/+1 counter on Arcbound Reclaimer. You can then use that very counter to fuel Arcbound Reclaimer's ability, recycling Delif's Cone straight from the graveyard back to the top of your library to keep the cycle spinning.