Akuta, Born of Ash

Haste
At the beginning of your upkeep, if you have more cards in hand than each opponent, you may sacrifice a Swamp. If you do, return Akuta from your graveyard to the battlefield.

Gollum, Obsessed Stalker

Skulk (This creature can't be blocked by creatures with greater power.)
At the beginning of your end step, each opponent dealt combat damage this game by a creature named Gollum, Obsessed Stalker loses life equal to the amount of life you gained this turn.

Ayara, First of Locthwain

Whenever Ayara or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Gríma Wormtongue

Your opponents can't gain life.
{T}, Sacrifice another creature: Target player loses 1 life. If the sacrificed creature was legendary, amass Orcs 2.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Baneful Omen

At the beginning of your end step, you may reveal the top card of your library. If you do, each opponent loses life equal to that card's mana value.

Archfiend of Ifnir

Flying
Whenever you cycle or discard another card, put a -1/-1 counter on each creature your opponents control.
Cycling {2} ({2}, Discard this card: Draw a card.)

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the greatest mana value among creatures and planeswalkers they control.

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.