Nim Deathmantle + Ashnod's Altar + Maulfist Squad

Nim Deathmantle

Ashnod's Altar

Maulfist Squad

How it works

1. Activate Ashnod's Altar by sacrificing Maulfist Squad, adding CC.
2. When Maulfist Squad dies, Nim Deathmantle triggers, causing you to pay 4 to return Maulfist Squad from your graveyard to the battlefield, and attach Nim Deathmantle to it.
3. When Maulfist Squad enters the battlefield, its fabricate ability triggers, creating a 1/1 Servo artifact creature token.
4. Activate Ashnod's Altar by sacrificing the Servo, adding CC.
5. Repeat.

This loop sets up an efficient self-sustaining cycle using Maulfist Squad as both the fuel and the recurring threat, while Ashnod's Altar provides the colorless mana needed to fund the operation. Whenever Maulfist Squad is sacrificed to the Altar, its death triggers Nim Deathmantle, which demands a four-mana investment to return the creature to the battlefield and reattach itself. Fortunately, Maulfist Squad's fabricate ability enters the fray by spawning a 1/1 Servo artifact creature token, which you can immediately feed to Ashnod's Altar along with the mana generated from earlier steps to pay for the Deathmantle's resurrection cost.