Nim Deathmantle + Ashnod's Altar + Siege Veteran

Nim Deathmantle

Ashnod's Altar

Siege Veteran

How it works

1. Activate Ashnod's Altar by sacrificing another nontoken Soldier, adding CC.
2. The Soldier dies, triggering Seige Veteran and Nim Deathmantle.
3. Resolve the Siege Veteran trigger, creating a 1/1 Soldier artifact creature token.
4. Activate Ashnod's Altar by sacrificing the Soldier, adding CC.
5. Resolve the Nim Deathmantle trigger from step 2, causing you to pay 4 to return the nontoken Soldier from your graveyard to the battlefield, and attach Nim Deathmantle to it.
6. Repeat.