Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Goblin Guide

Haste
Whenever this creature attacks, defending player reveals the top card of their library. If it's a land card, that player puts it into their hand.

Slickshot Show-Off

Flying, haste
Whenever you cast a noncreature spell, this creature gets +2/+0 until end of turn.
Plot {1}{R} (You may pay {1}{R} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Rift Bolt

Rift Bolt deals 3 damage to any target.
Suspend 1—{R} (Rather than cast this card from your hand, you may pay {R} and exile it with a time counter 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.)

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Monstrous Rage

Target creature gets +2/+0 until end of turn. Create a Monster Role token attached to it. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample.)

Bomat Courier

Haste
Whenever this creature attacks, exile the top card of your library face down. (You can't look at it.)
{R}, Discard your hand, Sacrifice this creature: Put all cards exiled with this creature into their owners' hands.

Fugitive Codebreaker

Prowess, haste
Disguise {5}{R}. This cost is reduced by {1} for each instant and sorcery card in your graveyard. (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this creature is turned face up, discard your hand, then draw three cards.

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.

Mountain

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)