Timothar, Baron of Bats + Eternal Scourge + Ashnod's Altar + Maskwood Nexus

Timothar, Baron of Bats

Eternal Scourge

Ashnod's Altar

Maskwood Nexus

How it works

1. Activate Ashnod's Altar by sacrificing Eternal Scourge, adding CC.
2. When Eternal Scourge dies as a Vampire due to Maskwood Nexus, Timothar triggers, causing you to pay 1 and exile Eternal Scourge to create a 1/1 Bat creature token.
3. Activate Ashnod's Altar by sacrificing the Bat, adding CC.
4. Cast Eternal Scourge from exile by paying 3.
5. Repeat.

This engine turns the graveyard into a revolving door thanks to a clever interplay of types and exile mechanics. Maskwood Nexus does the heavy lifting up front by making your creatures every type, which allows Timothar, Baron of Bats to recognize Eternal Scourge as a Vampire whenever it hits the graveyard. From there, you sacrifice Eternal Scourge to Ashnod's Altar for mana, use a tiny fraction of that return to exile it under Timothar in exchange for a Bat token, and sacrifice that Bat back to Ashnod's Altar to fund casting Eternal Scourge straight back out of exile. Because Eternal Scourge has the unique ability to be cast from exile, you break even on the mana while generating an endless loop of sacrifices, enters-the-battlefield triggers, and storm count.