Spark Elemental

Trample, haste (This creature can deal excess combat damage to the player or planeswalker it's attacking. This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Lightning Mare

This spell can't be countered.
This creature can't be blocked by blue creatures.
{1}{R}: This creature gets +1/+0 until end of turn.

Chandra, Acolyte of Flame

0: Put a loyalty counter on each red planeswalker you control.
0: Create two 1/1 red Elemental creature tokens. They gain haste. Sacrifice them at the beginning of the next end step.
−2: You may cast target instant or sorcery card with mana value 3 or less from your graveyard. If that spell would be put into your graveyard, exile it instead.

Spark Trooper

Trample, lifelink, haste
At the beginning of the end step, sacrifice this creature.

Call of the Death-Dweller

Return up to two target creature cards with total mana value 3 or less from your graveyard to the battlefield. Put a deathtouch counter on either of them. Then put a menace counter on either of them.

Swamp

Lightning Skelemental

Trample, haste
Whenever this creature deals combat damage to a player, that player discards two cards.
At the beginning of the end step, sacrifice this creature.

Thunderkin Awakener

Haste
Whenever this creature attacks, choose target Elemental creature card in your graveyard with toughness less than this creature's toughness. Return that card to the battlefield tapped and attacking. Sacrifice it at the beginning of the next end step.

Lightning Axe

As an additional cost to cast this spell, discard a card or pay {5}.
Lightning Axe deals 5 damage to target creature.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Haggle

You may discard a card. If you do, draw a card. (Then exile this card. You may cast the creature later from exile.)

Merchant of the Vale

Merchant of the Vale // Haggle

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Insolent Neonate

Menace (This creature can't be blocked except by two or more creatures.)
Discard a card, Sacrifice this creature: Draw a card.

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Mountain

Rix Maadi Reveler

Spectacle {2}{B}{R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
When this creature enters, discard a card, then draw a card. If this creature's spectacle cost was paid, instead discard your hand, then draw three cards.