Activate Ashnod's Altar by sacrificing Ministrant of Obligation, adding CC.
When Ministrant of Obligation dies, it and Nim Deathmantle trigger,
Resolve the Ministrant of Obligation trigger, creating two creature tokens.
Holding priority, activate Ashnod's Altar by sacrificing a creature token, adding CC.
Resolve the Nim Deathmantle trigger, causing you to pay 4 to return Ministrant of Obligation from your graveyard to the battlefield and attach Nim Deathmantle to it.
Repeat.
This clever loop begins by sacrificing the Ministrant of Obligation to Ashnod's Altar, which immediately generates two colorless mana to help fund the engine while triggering its Afterlife 2 ability to flood the board with two 1/1 Spirit tokens. As the Ministrant hits the graveyard, Nim Deathmantle's triggered ability steps in, letting you spend four mana to return the Ministrant directly to the battlefield equipped with the Deathmantle itself. You can easily sustain this endless loop by sacrificing one of the Spirit tokens to Ashnod's Altar for the remaining mana needed, creating an infinitely repeating cycle of sacrifice, resurrection, and token generation.