Amunet, Tyrants' End - Queen Marchesa (SLD-1559) - Secret Lair Drop / Amunet, Tyrants' End (Borderless)

Deathtouch, haste
When Queen Marchesa enters, you become the monarch.
At the beginning of your upkeep, if an opponent is the monarch, create a 1/1 black Assassin creature token with deathtouch and haste.