Gehaldirah sought to achieve reincarnation and he succeeded. It is with his understanding of life that he repurposed the artifact for punishing transcendents into separating the body of a Sovereign. A complete body of law of a Sovereign is vastly different from a soul body of a transcendent. It is a feat on its own to destroy the body without the soul.
Without life essence, his soul wouldn't have been able to heal when he destroyed his body to separate it from his soul. That feat alone of becoming an origin god with just his soul is the foundation for his reincarnation. It created a deficit in his existence that the universe sought to fill up with bodies.
His knowledge of arrays allowed him to create a formation capable of teleporting his soul into the law matrix by using the seed of a Sovereign as the key to it and other body parts as the destination within the law matrix.