Supermassive Black Hole

{3}{u}{b}, {t}: Target opponent draws seven
cards. That player takes an extra turn after their next turn. You control that player
during their next extra turn.
{3}, Discard a card: Exile target permanent.
You gain 3 life. Any player may activate this
ability during their extra turns.
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https://www.youtube.com/watch?v=Xsp3_a-PMTw