Unearth

Unearth is a keyword ability introduced in Shards of Alara as the Grixis signature mechanic.

Description
Unearth returns a creature to the battlefield and gives it haste, at the expense of the creature being exiled at the end of turn. It functions similarly to flashback, providing a one-time effect that can be cast from the graveyard. However, flashback only appears on instants and sorceries, and Unearth is strictly limited to creature cards.

History
Unearth was designed by Brian Tinsman, Devin Low and Erik Lauer. After Shards of Alara it also appeared in the other sets of the Alara block and in Modern Horizons.

The Encore mechanic introduced in Commander Legends is similar to Unearth, with subtle differences. Creatures with Unearth use the card itself, do not necessarily have to attack and are exiled at end of turn or if they leave the battlefield.

Rulings

 * Unearth appears only on creature cards.
 * You may activate the unearth ability of a card in your graveyard no matter how it wound up in your graveyard.
 * If you activate a card's unearth ability but if that card is removed from your graveyard before the ability resolves, that unearth ability will resolve and do nothing.
 * Activating a creature card's unearth ability isn't the same as casting the creature card. The unearth ability is put on the stack, but the creature card is not. Spells and abilities that interact with activated abilities (such as Stifle) will interact with unearth, but spells and abilities that interact with spells (such as Remove Soul) will not.
 * At the beginning of the next end step, a creature returned to the battlefield with unearth is exiled. This is a delayed triggered ability, and it can be countered by effects such as Stifle or Voidslime that counter triggered abilities. If the ability is countered, the creature will stay on the battlefield and the delayed trigger won't trigger again. However, the replacement effect will still exile the creature when it eventually leaves the battlefield.
 * Unearth grants haste to the creature that's returned to the battlefield. However, neither of the "exile" abilities is granted to that creature. If that creature loses all its abilities, it will still be exiled at the beginning of the next end step, and if it would leave the battlefield, it is still exiled instead.
 * If a creature returned to the battlefield with unearth would leave the battlefield for any reason, it's exiled instead unless the spell or ability that's causing the creature to leave the battlefield is actually trying to exile it. In that case, it succeeds in exiling it. If it later returns the creature card to the battlefield (as Oblivion Ring or Flickerwisp might, for example), the creature card will return as a new object with no relation to its previous existence. The unearth effect will no longer apply to it.

Creature that grants Unearth

 * Sedris, the Traitor King
 * Dregscape Sliver

Plane card that grants Unearth

 * Grixis</c> (blue, black, and/or red creature cards in your graveyard)

Trivia

 * Unearth was featured as rules card 3 of 5 in the Shards of Alara set.
 * Unearth was considered as a returning mechanic for Innistrad. It was also considered for the Golgari in Guilds of Ravnica, but it just didn't blend in with the guilds around it.
 * Unearth's playtest name was "Flashdance" based on the Flashback mechanic and the reanimation card Dance of the Dead</c>.