Living Plane

All lands are 1/1 creatures that are still lands.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Myr Moonvessel

Korvold, Fae-Cursed King

Flying
Whenever Korvold enters or attacks, sacrifice another permanent.
Whenever you sacrifice a permanent, put a +1/+1 counter on Korvold and draw a card.

Ashnod's Altar

Su-Chi

When this creature dies, add {C}{C}{C}{C}.

Juri, Master of the Revue

Whenever you sacrifice a permanent, put a +1/+1 counter on Juri.
When Juri dies, it deals damage equal to its power to any target.