Gravebreaker Lamia

Lifelink
When Gravebreaker Lamia enters, search your library for a card, put it into your graveyard, then shuffle.
Spells you cast from your graveyard cost {1} less to cast.

Dreadbringer Lampads

Constellation — Whenever Dreadbringer Lampads or another enchantment you control enters, target creature gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Araumi of the Dead Tide

{T}, Exile cards from your graveyard equal to the number of opponents you have: Target creature card in your graveyard gains encore until end of turn. The encore cost is equal to its mana cost. (Exile the creature card and pay its mana cost: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Protean Thaumaturge

Constellation — Whenever an enchantment you control enters, you may have Protean Thaumaturge become a copy of another target creature, except it has this ability.

Whitewater Naiads

Constellation — Whenever Whitewater Naiads or another enchantment you control enters, target creature can't be blocked this turn.

Doomwake Giant

Constellation — Whenever Doomwake Giant or another enchantment you control enters, creatures your opponents control get -1/-1 until end of turn.

Shoal Kraken

Constellation — Whenever an enchantment you control enters, you may draw a card. If you do, discard a card.

Thoughtrender Lamia

Constellation — Whenever Thoughtrender Lamia or another enchantment you control enters, each opponent discards a card.

Grim Guardian

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

Master of the Feast

Flying
At the beginning of your upkeep, each opponent draws a card.

Sage of Mysteries

Constellation — Whenever an enchantment you control enters, target player mills two cards.

Lampad of Death's Vigil

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

Thassa's Devourer

Constellation — Whenever Thassa's Devourer or another enchantment you control enters, target player mills two cards.

Nightmare Shepherd

Flying
Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and it's a Nightmare in addition to its other types.

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Erebos, Bleak-Hearted

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature.
Whenever another creature you control dies, you may pay 2 life. If you do, draw a card.
{1}{B}, Sacrifice another creature: Target creature gets -2/-1 until end of turn.

Kuon's Essence

At the beginning of each player's upkeep, that player sacrifices a creature of their choice.

Kuon, Ogre Ascendant

At the beginning of the end step, if three or more creatures died this turn, flip Kuon, Ogre Ascendant.