Davriel, Spell Hoarder

+2: Target player discards a card.
-2: Target opponent reveals their hand. You choose a nonland card from it. Exile that card. You may cast it if it's an instant or sorcery card.
-5: Exile all cards from all opponents' graveyards. You may cast them, and you may spend mana as though it were mana of any type to cast them.