Kindle the Inner Flame

Create a token that's a copy of target creature you control, except it has haste and "At the beginning of the end step, sacrifice this token."
Flashback—{1}{R}, Behold three Elementals. (You may cast this card from your graveyard for its flashback cost. Then exile it. To behold an Elemental, choose an Elemental you control or reveal an Elemental card from your hand.)

Negate

Prismabasher

Trample
Vivid — When this creature enters, up to X target creatures you control get +X/+X until end of turn, where X is the number of colors among permanents you control.

Mountain

Shimmercreep

Menace (This creature can't be blocked except by two or more creatures.)
Vivid — When this creature enters, each opponent loses X life and you gain X life, where X is the number of colors among permanents you control.

Flamebraider

{T}: Add two mana in any combination of colors. Spend this mana only to cast Elemental spells or activate abilities of Elemental sources.

Eclipsed Flamekin

When this creature enters, look at the top four cards of your library. You may reveal an Elemental, Island, or Mountain card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Eddymurk Crab

Flash
This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
This creature enters tapped if it's not your turn.
When this creature enters, tap up to two target creatures.

Explosive Prodigy

Vivid — When this creature enters, it deals X damage to target creature an opponent controls, where X is the number of colors among permanents you control.

Flaring Cinder

When this creature enters and whenever you cast a spell with mana value 4 or greater, you may discard a card. If you do, draw a card.

Spell Snare

Kithkeeper

Vivid — When this creature enters, create X 1/1 green and white Kithkin creature tokens, where X is the number of colors among permanents you control.
Tap three untapped creatures you control: This creature gets +3/+0 and gains flying until end of turn.

Stock Up

Look at the top five cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Island

Essence Scatter

Noggle the Mind

Flash
Enchant creature
Enchanted creature loses all abilities and is a colorless Noggle with base power and toughness 1/1. (It loses all colors and all other creature types.)