Thermokarst

Destroy all white permanents.

At the beginning of your upkeep, put a time counter on this artifact. 1, T, Sacrifice this artifact: This artifact deals damage equal to the number of time counters on it to each creature and each player.

Enchant creature At the beginning of the upkeep of enchanted creature's controller, that player may pay 3. If they don't, this Aura deals 2 damage to that player and you tap that creature.

Flare deals 1 damage to any target. Draw a card at the beginning of the next turn's upkeep.

At the beginning of your upkeep, sacrifice this enchantment unless you pay 2. Whenever a creature dies, that creature's controller sacrifices a land of their choice.

This creature has trample as long as you control a snow land.

Until end of turn, whenever a creature you control attacks and isn't blocked, you may choose to have it deal damage equal to its power to a target creature. If you do, it assigns no combat damage this turn.

Blocking creatures get +1/+1 until end of turn.