Geothermal Bog

({T}: Add {B} or {R}.)
This land enters tapped.

Swamp

Caldera Breaker

Trample
When Caldera Breaker enters, exile all Mountain cards from your library. When you do, Caldera Breaker deals that much damage to target creature or planeswalker an opponent controls.
When Caldera Breaker dies, put all cards exiled with it onto the battlefield under their owner's control. Conjure four cards named Volcanic Geyser into your library, then shuffle.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Crucias, Titan of the Waves

At the beginning of your end step, you may discard a card. If you do, create a Treasure token and choose ambitious or expedient. If you chose ambitious, seek a card with greater mana value than the discarded card. If you chose expedient, seek a card with lesser mana value than the discarded card.

Mountain

Raucous Theater

({T}: Add {B} or {R}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)