This requires Jace, Vryn's Prodigy. After getting at least five cards in your graveyard, Jace will transform to Jace, Telepath Unbound, which has 5 loyalty. You need at least 6, however. Keep Jace on the board and have at least two sorcery or instant in your graveyard. When possible, use his second ability [-3]: "You may cast target instant or sorcery card from your graveyard this turn". If that card would be placed into your graveyard that turn, exile it instead. Do this twice.