Reckless Ransacking

Target creature gets +3/+2 until end of turn. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Hexing Squelcher

This spell can't be countered.
Ward—Pay 2 life.
Spells you control can't be countered.
Other creatures you control have "Ward—Pay 2 life."

Firdoch Core

Changeling (This card is every creature type.)
{T}: Add one mana of any color.
{4}: This artifact becomes a 4/4 artifact creature until end of turn.

Flamekin Gildweaver

Trample
When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Flamebraider

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

Glen Elendra's Answer

This spell can't be countered.
Counter all spells your opponents control and all abilities your opponents control. Create a 1/1 blue and black Faerie creature token with flying for each spell and ability countered this way.

Temporal Cleansing

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
The owner of target nonland permanent puts it into their library second from the top or on the bottom.

Lofty Dreams

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Enchant creature
When this Aura enters, draw a card.
Enchanted creature gets +2/+2 and has flying.

Stalactite Dagger

When this Equipment enters, create a 1/1 colorless Shapeshifter creature token with changeling. (It's every creature type.)
Equipped creature gets +1/+1 and is all creature types.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Mountain

Unexpected Assistance

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Draw three cards, then discard a card.

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.

Thirst for Identity

Draw three cards. Then discard two cards unless you discard a creature card.

Aquitect's Defenses

Flash
Enchant creature you control
When this Aura enters, enchanted creature gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)
Enchanted creature gets +1/+2.

Island

Wild Unraveling

As an additional cost to cast this spell, blight 2 or pay {1}. (To blight 2, put two -1/-1 counters on a creature you control.)
Counter target spell.

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.

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.

Summit Sentinel

Kulrath Mystic

Whenever you cast a spell with mana value 4 or greater, this creature gets +2/+0 and gains vigilance until end of turn.

Gristle Glutton

{T}, Blight 1: Discard a card. If you do, draw a card. (To blight 1, put a -1/-1 counter on a creature you control.)

Feed the Flames

Feed the Flames deals 5 damage to target creature. If that creature would die this turn, exile it instead.

Sizzling Changeling

Changeling (This card is every creature type.)
When this creature dies, exile the top card of your library. Until the end of your next turn, you may play that card.

Cinder Strike

As an additional cost to cast this spell, you may blight 1. (You may put a -1/-1 counter on a creature you control.)
Cinder Strike deals 2 damage to target creature. It deals 4 damage to that creature instead if this spell's additional cost was paid.

Spell Snare

Squawkroaster

Double strike
Vivid — Squawkroaster's power is equal to the number of colors among permanents you control.

Enraged Flamecaster

Reach
Whenever you cast a spell with mana value 4 or greater, this creature deals 2 damage to each opponent.