Corpse Connoisseur

If you activate a card’s unearth ability but that card is removed from your graveyard before the ability resolves, that unearth ability will resolve and do nothing.

At the beginning of the 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 end step, and if it would leave the battlefield, it is still exiled instead.