Harmony

Long ago, the world was in threat of being torn out of balance. Three powerful mages had been born at the same time, each with very different morals and opinions on how their magic should be used. To save the world, one of the kings invoked a forbidden spell, cursing himself and the other two Kings and ripping their souls apart, intending to destroy all three of them forever - however with a new threat beginning to grow the gods have resurrected these three mages - along with their slightly less knowledgeable other halves.

The kings are fully aware of their past lives and the power them can control - only issue is, the can't draw on much magic at all without their soulmate...and their soulmates have no idea the type of destiny that awaits them.