Eidolon of the Great Revel

Whenever a player casts a spell with mana value 3 or less, Eidolon of the Great Revel deals 2 damage to that player.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Mountain

Seek the Beast

Exile the top two cards of your library. Until your next end step, you may play those cards.

Questing Druid

Whenever you cast a spell that's white, blue, black, or red, put a +1/+1 counter on Questing Druid.

Questing Druid // Seek the Beast

Goblin Guide

Haste
Whenever Goblin Guide attacks, defending player reveals the top card of their library. If it's a land card, that player puts it into their hand.

Taiga

Loam Lion

Loam Lion gets +1/+2 as long as you control a Forest.

Plateau

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Kird Ape

Kird Ape gets +1/+2 as long as you control a Forest.

Wild Nacatl

Wild Nacatl gets +1/+1 as long as you control a Mountain.
Wild Nacatl gets +1/+1 as long as you control a Plains.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Fireblast

You may sacrifice two Mountains rather than pay this spell's mana cost.
Fireblast deals 4 damage to any target.

Arid Mesa

{T}, Pay 1 life, Sacrifice Arid Mesa: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.