Generated Horizons

At the beginning of each upkeep, untap all creatures and lands.

At the beginning of your upkeep, populate. (Create a token that's a copy of a creature token you control.)

At the beginning of your upkeep, create a 1/1 colorless Spirit creature token for each Shrine you control.

At the beginning of your upkeep, this creature deals 1 damage to you.

Oozes you control get +1/+1.

At the beginning of your upkeep, if you control a commander, create a token that's a copy of this creature.

At the beginning of your upkeep, if you control twenty or more creatures, you win the game.