Survey Mechan + Mortuary + Ashnod's Altar + Anointed Procession + Skeleton Crew

Survey Mechan

Mortuary

Ashnod's Altar

Anointed Procession

Skeleton Crew

How it works

1. Activate Survey Mechan by sacrificing it.
2. When Survey Mechan dies, Mortuary triggers, putting Survey Mechan from your graveyard onto the top of your library.
3. Skeleton Crew triggers, creating two creature tokens.
4. Resolve the Survey Mechan ability, dealing 3 damage to any target and causing you to draw three cards and gain 3 life.
5. Activate Ashnod's Altar twice by sacrificing the two creature tokens, adding CCCC.
6. Cast Survey Mechan by paying 4.
7. Repeat.

This loop relies on Survey Mechan as the expendable engine, whose massive activation cost is heavily discounted by your diverse lands so it can be repeatedly cast for just four mana. When you sacrifice Survey Mechan to its own ability, Mortuary immediately intercepts it upon death to place it right back on top of your library, ensuring you always have access to it for your next draw. Meanwhile, Skeleton Crew watches Survey Mechan leave your graveyard to trigger its token creation, which is doubled into two tokens thanks to the replacement effect of Anointed Procession. You then feed those generated tokens directly into Ashnod's Altar to easily generate the four mana needed to recast Survey Mechan from the top of your library and do it all over again.