Demon of Dark Schemes + Phyrexian Altar + Sengir Autocrat

Demon of Dark Schemes

Phyrexian Altar

Sengir Autocrat

How it works

1. Cast Sengir Autocrat by paying 3.
2. Sengir Autocrat enters the battlefield, creating three 0/1 Serf creature tokens.
3. Activate Phyrexian Altar three times by sacrificing the Serf tokens, adding 2.
4. Demon of Dark Schemes triggers three times, causing you to get EEE.
5. Activate Phyrexian Altar by sacrificing Sengir Autocrat, adding one mana of any color.
6. Demon of Dark Schemes triggers, causing you to get E.
7. Activate Demon of Dark Schemes by paying 2 and EEEE, putting Sengir Autocrat from your graveyard onto the battlefield tapped.
8. Repeat from step 2.

This loop transforms the humble Serf tokens into a self-sustaining engine of mana and energy. When you cast Sengir Autocrat, its entry triggers the creation of those three tokens, which are immediately fed alongside the Autocrat itself into Phyrexian Altar to generate the necessary mana. Meanwhile, Demon of Dark Schemes watches every single one of those deaths from the battlefield, steadily accumulating the energy counters required to activate its own resurrection ability. By paying that energy and mana back into the Demon, you pull the Autocrat straight out of the graveyard and right back onto the battlefield to restart the cycle anew.