Circular Logic

Counter target spell unless its controller pays {1} for each card in your graveyard.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Kitchen Imp

Flying, haste
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Gorilla Shaman

{X}{X}{1}: Destroy target noncreature artifact with mana value X.

Fiery Temper

Fiery Temper deals 3 damage to any target.
Madness {R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Shimmerdrift Vale

This land enters tapped.
As this land enters, choose a color.
{T}: Add one mana of the chosen color.

Snow-Covered Swamp

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Snow-Covered Island

Skred

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

Pilfering Hawk

Flying
{S}, {T}: Draw a card, then discard a card. ({S} can be paid with one mana from a snow source.)

Sneaky Snacker

Flying
When you draw your third card in a turn, return this card from your graveyard to the battlefield tapped.

Grab the Prize

As an additional cost to cast this spell, discard a card.
Draw two cards. If the discarded card wasn't a land card, Grab the Prize deals 2 damage to each opponent.

Breath Weapon

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

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Alms of the Vein

Target opponent loses 3 life and you gain 3 life.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Seething Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.
Cycling {U}{B}{R} ({U}{B}{R}, Discard this card: Draw a card.)

Cast into the Fire

Choose one —
• Cast into the Fire deals 1 damage to each of up to two target creatures.
• Exile target artifact.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Nihil Spellbomb

{T}, Sacrifice this artifact: Exile target player's graveyard.
When this artifact is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Vampire's Kiss

Target player loses 2 life and you gain 2 life. Create two Blood tokens. (They're artifacts with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")