Bond Soulmates

 An ancient ritual invented by the love goddess Sune eons ago and then passed down to her most powerful and elite clerics as a mark of her favor. Two souls bonded by this ritual cannot be parted by death and will eternally reincarnate as lovers, friends, family, etc. of each other upon death, over and over again until the bond is either dispelled or one or both souls are destroyed or the Astral Plane is destroyed or otherwise rendered inaccessible to the dead's souls.