In contrast to the Double Life Reincarnation Technique, which required two bodies with precisely identical Soul Essence to fuse together, the Soulstream Fusion Divine Art achieved fusion through the Thread of Eternal Bond.
The Thread of Eternal Bond served as the connection that linked the soul and their inherited or possessed bodies throughout multiple lifetimes.
What is the Thread of Eternal Bond?
Thread of Eternal Bond is a rare thread that binds souls together across lifetimes. Those connected by this thread share a deep and unbreakable bond, and exactly this bond could make Ling Xiaolong's three different bodies that share the same soul but different Soul Essence fuse together while keeping each other's everything.
When Ling Xiaolong was creating the Soulstream Fusion Divine Art, he was in a mysterious state of enlightenment, so deep that it felt like he was sleeping profoundly and this state could have continued for eternity.