Mortuary + Digsite Conservator + Ashnod's Altar + Pawn of Ulamog

Mortuary

Digsite Conservator

Ashnod's Altar

Pawn of Ulamog

How it works

1. Activate Ashnod's Altar by sacrificing Digsite Conservator, adding CC.
2. When Digsite Conservator dies, it, Mortuary and Pawn of Ulamog trigger.
3. Resolve the Pawn of Ulamog trigger, creating a 0/1 Eldrazi Spawn creature token.
4. Activate Ashnod's Altar by sacrificing the Eldrazi Spawn, adding CC.
5. Resolve the Mortuary trigger, putting Digsite Conservator on top of your library from your graveyard.
6. Resolve the Digsite Conservator trigger, causing you to pay 4 to exile Digsite Conservator from the top of your library and cast it without paying its mana cost.
7. Repeat.

This clever loop turns the cycle of life and death into an endless engine using Ashnod's Altar to sacrifice your creatures for mana. When you feed Digsite Conservator to the altar, Pawn of Ulamog immediately steps in to generate a disposable Eldrazi Spawn token that fuels the remaining mana needed to pay for the conservator's death trigger. Meanwhile, Mortuary ensures that Digsite Conservator never stays in the graveyard long, constantly returning it to the top of your library so the discover ability can recast it right back onto the battlefield.