Agent of Amnesia

Nightmare (When this card dies, return it to the battlefield under target opponent's control)
At the beginning of your upkeep, discard a card and send the top two cards of your library to the graveyard. Activate only if you control, but do not own, Agent of Amnesia.
At the beginning of your endstep, you may reveal your hand and have target opponent select a card from it, discard that card and exile Agent of Amnesia.