Snowfield Sinkhole

({T}: Add {W} or {B}.)
Snowfield Sinkhole enters tapped.

Wicked Visitor

Whenever an enchantment you control is put into a graveyard from the battlefield, each opponent loses 1 life.

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Grim Guardian

Constellation — Whenever Grim Guardian or another enchantment you control enters, each opponent loses 1 life.

Dog Umbra

Flash
Enchant creature
As long as another player controls enchanted creature, it can't attack or block. Otherwise, Dog Umbra has umbra armor. (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Swamp

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.)

Balemurk Leech

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, each opponent loses 1 life.

Orzhov Basilica

Orzhov Basilica enters tapped.
When Orzhov Basilica enters, return a land you control to its owner's hand.
{T}: Add {W}{B}.

Candy Grapple

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Target creature gets -3/-3 until end of turn. If this spell was bargained, that creature gets -5/-5 until end of turn instead.

Kor Skyfisher

Flying
When Kor Skyfisher enters, return a permanent you control to its owner's hand.

Hopeless Nightmare

When Hopeless Nightmare enters, each opponent discards a card and loses 2 life.
When Hopeless Nightmare is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice Hopeless Nightmare.

Lampad of Death's Vigil

{1}, Sacrifice a creature: Each opponent loses 1 life and you gain 1 life.

Plains

Fear of Lost Teeth

When Fear of Lost Teeth dies, it deals 1 damage to any target and you gain 1 life.