Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Voldaren Epicure

When Voldaren Epicure enters, it deals 1 damage to each opponent. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Goblin Blast-Runner

Goblin Blast-Runner gets +2/+0 and has menace as long as you sacrificed a permanent this turn.

Mountain

Implement of Combustion

{R}, Sacrifice Implement of Combustion: It deals 1 damage to target player or planeswalker.
When Implement of Combustion is put into a graveyard from the battlefield, draw a card.

Improvised Club

As an additional cost to cast this spell, sacrifice an artifact or creature.
Improvised Club deals 4 damage to any target.

Wrenn's Resolve

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Reckless Impulse

Kuldotha Rebirth

As an additional cost to cast this spell, sacrifice an artifact.
Create three 1/1 red Goblin creature tokens.

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.)

Monastery Swiftspear

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

Experimental Synthesizer

When Experimental Synthesizer enters or leaves the battlefield, exile the top card of your library. Until end of turn, you may play that card.
{2}{R}, Sacrifice Experimental Synthesizer: Create a 2/2 white Samurai creature token with vigilance. Activate only as a sorcery.