Diokoros, the Fate Snipper

Flying, Hexproof
Whenever an opponent casts an instant or sorcery that targets a permanent you control, you may copy that spell. If you do, the copy of that spell targets a permanent another player controls if able.
{1}{u}{b}{r},{t}: Target opponent reveals their hand.
You may choose an instant or sorcery from among them. That spell gains flash and costs {0} this turn, then that player must cast that spell. Activate this ability only as a sorcery.