Kess, Dissident Mage

If a spell cast this way is put into another zone after it resolves (perhaps because it had buyback), it's considered a new object. If that card later moves to your graveyard, it won't be exiled.

If a sorcery card is put into your graveyard during your main phase and the stack is empty, you have a chance to cast it before any player may attempt to remove that card from your graveyard.

If you cast one instant or sorcery card from your graveyard and then have a new Kess come under your control in the same turn, you may cast another instant or sorcery card from your graveyard that turn.