Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Breath Weapon

Breath Weapon deals 2 damage to each non-Dragon creature.

Magmatic Sinkhole

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Magmatic Sinkhole deals 5 damage to target creature or planeswalker.

Mycosynth Wellspring

When Mycosynth Wellspring enters or is put into a graveyard from the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Skred

Skred deals damage to target creature equal to the number of snow permanents you control.

Improvised Club

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

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Lembas

When Lembas enters, scry 1, then draw a card.
{2}, {T}, Sacrifice Lembas: You gain 3 life.
When Lembas is put into a graveyard from the battlefield, its owner shuffles it into their library.

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Kuldotha Rebirth

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

Kami of Industry

When Kami of Industry enters, return target artifact card with mana value 3 or less from your graveyard to the battlefield. It gains haste. Sacrifice it at the beginning of the next end step.

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Snow-Covered Mountain

Candy Trail

When Candy Trail enters, scry 2.
{2}, {T}, Sacrifice Candy Trail: You gain 3 life and draw a card.