Phyrexian Altar + Chthonian Nightmare + Weaponcraft Enthusiast

Phyrexian Altar

Chthonian Nightmare

Weaponcraft Enthusiast

How it works

1. Cast Chthonian Nightmare by paying 1.
2. When Chthonian Nightmare enters, it triggers, causing you to get EEE.
3. Activate Chthonian Nightmare by paying EEE, sacrificing a creature and returning Chthonian Nightmare from the battlefield to your hand, returning Weaponcraft Enthusiast from your graveyard to your hand.
4. When Weaponcraft Enthusiast enters, it triggers, creating two 1/1 Servo artifact creature tokens.
5. Activate Phyrexian Altar twice by sacrificing Weaponcraft Enthusiast and a Servo, adding 1.
6. Repeat.

This elegant loop relies on Chthonian Nightmare to constantly resurrect threats while fueling its own energy costs through the sacrifice of generated bodies. By casting Weaponcraft Enthusiast, its Fabricate 2 ability immediately supplies two Servo artifact creature tokens alongside the artificer herself to feed the engine. You can then use Phyrexian Altar to sacrifice those extra bodies for the mana needed to replay the enchantment, while the Nightmare's own bounce ability loops it safely back to your hand.