Well, there are three, but only one is really usable in activities where it'd matter..If the "Heroic" mode of King's Fall gave us a Void Exotic Primary, and then the Vex Mythoclast got a Year 2 version, we'd be pretty covered. Necrochasm as well but the Supercell already exists for Year 2 so it coming into Year 2 wouldn't have as big of an impact. They could always rework Elements into certain Exotic Primaries as well; like a Void Bad Juju.