Arcbound Reclaimer + Showdown of the Skalds + Mystic Forge + Tormod's Crypt

Arcbound Reclaimer

Showdown of the Skalds

Mystic Forge

Tormod's Crypt

How it works

1. Cast Tormod's Crypt 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 Tormod's Crypt by tapping and sacrificing it.
4. Activate Arcbound Reclaimer by removing a +1/+1 counter from it, putting Tormod's Crypt from your graveyard onto the top of your library.
5. Repeat.

By leveraging Mystic Forge, you can peer into the top of your library and cast Tormod's Crypt for zero mana straight off the top. Every time that zero-mana artifact hits the stack, the second chapter of Showdown of the Skalds triggers to safely place a +1/+1 counter onto Arcbound Reclaimer. You then sacrifice Tormod's Crypt to exile a graveyard, allowing Arcbound Reclaimer to spend that newly minted counter to recycle Tormod's Crypt right back to the top of your library. Repeating this loop feeds an endless cycle of artifact entry, sacrifice, and casting triggers.