Unstable Amulet

When Unstable Amulet enters, you get {E}{E} (two energy counters).
Whenever you cast a spell from anywhere other than your hand, Unstable Amulet deals 1 damage to each opponent.
{T}, Pay {E}{E}: Exile the top card of your library. You may play it until you exile another card with Unstable Amulet.

Modern Horizons 3

When Unstable Amulet enters the battlefield, you get {E}{E} (two energy counters).
Whenever you cast a spell from anywhere other than your hand, Unstable Amulet deals 1 damage to each opponent.
{T}, Pay {E}{E}: Exile the top card of your library. You may play it until you exile another card with Unstable Amulet.

When Unstable Amulet enters the battlefield, you get {E}{E}.
Whenever you cast a spell from anywhere other than your hand, Unstable Amulet deals 1 damage to each opponent.
{T}, Pay {E}{E}: Exile the top card of your library. You may play it until you exile another card with Unstable Amulet.

If Unstable Amulet leaves the battlefield before you play the most recently exiled card, you can play that card for as long as it remains exiled.

Unstable Amulet's second ability counts any spells cast from zones other than your hand. These are usually spells cast from exile, the graveyard, or the command zone. It also counts spells cast from outside the game, such as spells cast with Wish or Garth One-Eye's ability.

You pay all costs and follow all normal timing rules for cards played with Unstable Amulet's last ability. For example, if the exiled card is a land card, you may play it only during your main phase while the stack is empty.