(5x08) Pantheon Genesis: Part 3, Episode 2
Though initially only allies in the war against Kron, turning mostly to mortals for fleeting romantic flings, ruling the Pantheon and its client civilization on Auei has slowly brought Xio and Met emotionally closer. In time they become romantically engaged, and Met eventually becomes pregnant by Xio. Taking advantage of that situation, Kron secretly counsels Xio that, just as Kron overthrew Oron and Xio overthrew Kron, so too this child will grow to overthrow Xio in time, if Xio does nothing to stop it.
Oron, lost in space thanks to Kron but still capable of telepathic communication, reluctantly concurs with Kron. Though he condemns Kron's actions to imprison Xio's brethren just as he condemns Kron's actions against himself, Oron sees that through Kron's action a cycle of disruption has been established, one that now perpetuates itself. He believes that his family needs, now more than ever, stable leadership, and so he counsels Xio to take steps to prevent the next turn of the cycle, and gives him the tools to do so.
With great reluctance, Xio concedes and agrees to Oron's plan to prevent the doom that Kron had foretold. Oron taught Xio the psychic ability that he had been taught by Keius, sharing a power he had never dared share with anyone, and in doing so securing Xio's perpetual leadership. In case Keie had ever been trapped in some kind of unending torment on Earth, Oron had been taught how to use his psychic link to pull her mind from her body into his own mind, saving her from the torment and salvaging all of her valuable memories of life on Earth that they were put there to gather, though leaving her strangely disembodied. Using that power as psychically taught to him by Oron, Xio is able to strip his beloved Met's mind likewise out of her own body and into his mind, so that her body may die and their child with it, but they can still be together forever.
Met is, of course, understandably furious at being essentially murdered by her lover, and having her disembodied mind then trapped within the mind of the very murderer himself. From her place inside Xio's mind, she will not let him hear the end of it, boiling over in ceaseless righteous fury, the inefficacy of her rage only driving her into a further rage still. Being powerless to do anything else, she channels that hate and fury into hurting Xio emotionally, with a targeted precision that only someone literally inside his own mind with full access to its contents could obtain.
Xio tries to defend himself, to explain, to profess his good intentions and continued love for the one who is even then tearing him apart from the inside. But it is not enough, it can never be enough, and he soon realizes that there is no justification, no defense of his actions, he has made a terrible mistake that cannot be undone and, as Met's disembodied voice promises, he will now suffer for it endlessly for the rest of his immortal life. Terrified of that fate and full of self-hate blurring seamlessly with Met's constant white-hot fury, Xio begs another of the Pantheon to attempt to kill him, by destroying his head completely, and chaining him to a stone at the bottom of the ocean. The other hesitantly agrees, and off the northern shores of Indonesia in the shadow of their great tower, the dark deed is done, and seems to succeed.
Meanwhile, the entire attempt on Met's life turns out to have been for naught, as thanks to their nanites, their child's body is reabsorbed back into the mother's, and the child's nanites take over that body, giving birth to a new full-grown woman, Aten. Despite being fully grown physically, her mind is that of the unborn child, and as such she has to be raised like a newborn child again. When asked, by her interviewer in the future Pacifica to whom Met is narrating all this, how she can possibly know about these events after not only she was killed, but the killer whose mind her mind was trapped in was killed, Met explains that that is a complicated later part of the story, and that everything from here out was either remembered by Xio—the relevance of that being another complicated later part of the story—or else taught to her by those who lived it, many thousands of years later.