Hushbringer

Flying, lifelink
Creatures entering the battlefield or dying don't cause abilities to trigger.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Phlage, Titan of Fire's Fury

When Phlage enters the battlefield, sacrifice it unless it escaped.
Whenever Phlage enters the battlefield or attacks, it deals 3 damage to any target and you gain 3 life.
Escape—{R}{R}{W}{W}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Doorkeeper Thrull

Flash
Flying
Artifacts and creatures entering the battlefield don't cause abilities to trigger.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Bitter Reunion

When Bitter Reunion enters the battlefield, you may discard a card. If you do, draw two cards.
{1}, Sacrifice Bitter Reunion: Creatures you control gain haste until end of turn.

Mountain

Kroxa, Titan of Death's Hunger

When Kroxa enters the battlefield, sacrifice it unless it escaped.
Whenever Kroxa enters the battlefield or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)