Yan Liang, Ruler of Traitors

Grave ninjutsu {u/r}{u/r}{b}{b} ({u/r}{u/r}{b}{b}, Return an unblocked attacker from you control to hand: Put this card onto the battlefield from your hand or graveyard tapped and attacking.)
Whenever Yan Liang deals combat damage to a player, that player exiles a card from their hand face down. As long as it remains exiled, you may look at and play that card, and you may spend mana as though it were mana o