Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Flooded Grove

{T}: Add {C}.
{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

Shardless Agent

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Forest

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Bathe in Gold

Create a Treasure token. (Then exile this card. You may cast the creature later from exile.)

Young Red Dragon

Young Red Dragon // Bathe in Gold

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Twinshot Sniper

Reach
When Twinshot Sniper enters, it deals 2 damage to any target.
Channel — {1}{R}, Discard Twinshot Sniper: It deals 2 damage to any target.

Mountain

Crashing Footfalls

Suspend 4—{G} (Rather than cast this card from your hand, pay {G} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Create two 4/4 green Rhino creature tokens with trample.

Harmonize

Island

Geological Appraiser

When Geological Appraiser enters, if you cast it, discover 3. (Exile cards from the top of your library until you exile a nonland card with mana value 3 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Plant Beans

You may play an additional land this turn. (Then exile this card. You may cast the creature later from exile.)

Beanstalk Wurm

Beanstalk Wurm // Plant Beans

Mossfire Valley

Overflowing Basin

Bloodbraid Elf

Haste
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Throes of Chaos

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

That's Mine

Grabby Giant

Reach
{2}{R}, Sacrifice an artifact or land: Draw a card.

Grabby Giant // That's Mine

Violent Outburst

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Creatures you control get +1/+0 until end of turn.