Ghostblood

When you cast this spell, each player exiles a card
at random from their hand face down with a
binding counter on it.
Target opponent returns a card at random from
their graveyard to their hand: Remove a binding counter from an exiled card, and turn it face up.
You may play that card, and you may spend
mana as though it were mana of any type to cast
it. If you don't, put it into its owner's graveyard.