Lightning Skelemental

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

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Kroxa, Titan of Death's Hunger

When Kroxa enters, sacrifice it unless it escaped.
Whenever Kroxa enters or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Collective Brutality

Escalate—Discard a card. (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Target opponent reveals their hand. You choose an instant or sorcery card from it. That player discards that card.
• Target creature gets -2/-2 until end of turn.
• Target opponent loses 2 life and you gain 2 life.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Pyroclasm

Pyroclasm deals 2 damage to each creature.

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Searstep Pathway

Blightstep Pathway

Blightstep Pathway // Searstep Pathway

Mountain

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.)

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.

Inquisition of Kozilek

Target player reveals their hand. You choose a nonland card from it with mana value 3 or less. That player discards that card.

Swamp

Light Up the Stage

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Thunderkin Awakener

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Dispersal

Each opponent returns a nonland permanent they control with the highest mana value among permanents they control to its owner's hand, then discards a card.

Discovery

Surveil 2, then draw a card. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Discovery // Dispersal

Hellspark Elemental

Trample, haste
At the beginning of the end step, sacrifice Hellspark Elemental.
Unearth {1}{R} ({1}{R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

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 Spark Elemental.

Insolent Neonate

Menace (This creature can't be blocked except by two or more creatures.)
Discard a card, Sacrifice Insolent Neonate: 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 Ball Lightning.

Snow-Covered Mountain

Smash to Smithereens

Destroy target artifact. Smash to Smithereens deals 3 damage to that artifact's controller.

Haggle

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