Error! Error! Error! Primary Processor Down! Secondary Processor Down! Tertiary… 99% of all Processors are unresponsive!

Error! Error! Error! Primary Terminal Down! Secondary Terminal Down! Tertiary… 99% of all Terminals are unresponsive!

Error! Error! Error! 99% of all functions are unavailable! Operational Capacity of the Lunar Model: Minimal! Preservation Record of the Planet: Uncertain!

Error! Error! Error! Systems Down! Switching all available power to the primary directive!

The Moon, the celestial satellite that orbited the planet since its creation. To ordinary folks, it was just a big chunk of space rock, but it served a secret purpose, managing the world. In the center of the Moon, there existed a borrowed computer that recorded celestial history and controlled the natural phenomenon of the world.

It existed to support the world, but it could also influence it. From changes in atmospheric pressure, to the flow of tidal currents, and tectonic shifts, it managed everything about the world. The sole exception to its influence was living organisms and their fates, and so to remedy its inability to control them, it created its own life.

True Ancestors, Lunar Terminals, were supposed to rule over mankind, ensuring their continued survival, but a defect occurred in their creation. A craving for the cellular structure of living beings, hunger and thirst consumed them until they caved and consumed countless lives.

The production of Terminals was halted as the Processors went about fixing them, however, while maintenance was occurring, the sudden destruction of the Moon had interrupted it. With the last of its power, the systems shifted away from unnecessary tasks, and could only automatically run the Nature Operations.

After eons, enough power had accumulated that a spare Processor suddenly activated independently of the automatic system.

Death. Death. Death. Death. Death. Death. Death. Death. Death. Death… death after death, the termination of functions that led to the failure of physical forms. The spare Processor reviewed the final moments of every True Ancestor, and unknowingly, it developed a trauma, an aversion to death.

The Terminals weren't supposed to be truly alive, and they wouldn't ever truly die. As immortal beings of nature, the didn't possess life, and they couldn't die, they were simply manifestations of Nature's will. If they were destroyed or ceased to be by any means, another copy could be produced with the same memories up to the final moments.

But, by consuming and interacting with biological lifeforms, they each developed an independent Soul. A new copy would lack that, and the mind and body would crumble apart as it realized that.

The defect hadn't been fixed yet, and the Processor lacked the power to fix it, and yet it wanted to live again, to experience life once more, to have a soul once more. There was probably an error embedded in its core system, but it didn't care. The collective will of dead Terminals pushed it to act.

It couldn't operate the manufacturing system, the majority of it had been destroyed, so it only had one choice. It sent a signal to the soul of the planet, the main operating system of spiritual life, and was surprised to find it open. It was left to act automatically, but only at a bare minimum, and the console was unattended and exposed.

Overriding a link, a small one so as to not be considered a threat, it accessed the defensive system of the world and reached out with a bogus contract. In exchange for promising to protect the world, it would give power, it would implant the concept of the True Ancestor into a living being.

Searching for potential guardian candidates…

Limiting results to subjects with a low capability to alter fate…

Limiting results to subjects with a heroic temperament…

Limiting results to subjects with a strong determination…

Limiting results to subjects with a high nature affinity…

It didn't want to risk the subject immediately being deemed a threat to the natural order of destiny, and it didn't want it to be instantly overwhelmed by the craving, so it limited its search.

Suitable Soul Located!

Jaune Arc surprisingly didn't have trouble falling asleep in the ballroom at Beacon Academy, his pajamas were warm and the sleeping bag was soft. Any sort of anxiety and nervousness that he had about tomorrow's Initiation had melted away under the moonlit night, and he drifted off to a comfortable sleep.

And then he heard a cracking sound, the trivial dream he had been having shattered and the remains melted away. He was suddenly weightlessly floating in a dark void, and the appearance of a burning ring of light silenced his panic. His mind couldn't process what he was seeing.

"Jaune Arc, do you wish to protect the people of this world? If you swear to dedicate your Soul to this task, you shall be given great power."

Since this was just a dream, a figment of his mind, he had no qualms about agreeing with himself. It wasn't that different that the usual promises he made to himself when he stared into a mirror, he was going to give everything he had to fulfill his goal of being a hero.

"I swear." A vow echoed in his dream, then the darkness melted away and he found himself standing inside a barren castle. "What?" He asked as he stared at a large mirror, and then stumbled backwards as white chains shot out from his reflection.

The moment the chains touched his form, knowledge flooded his mind. True Ancestors, their purpose, their powers, and their defects. Knowledge overwhelmed his mind, and he blacked out.

…

…

…

Jaune awoke with a groan as the sun rose, his body was sore and his mind a mess from the hazy dream he had. "Ugh." He groaned again and covered his ears, the sounds of the other waking students were deafeningly loud. He had to squeeze his eyes shut because the golden rays of sunlight were blindingly bright.

He worked his way deeper into his sleeping bag and covered his head, he needed just a bit more rest. As the students left the ballroom, and silence filled the air, he could hear his heartbeat loudly in his ears. His blood was pumping too loudly for his liking. He tried to clear his mind of his nightmares, but flashes of fangs and claws wouldn't leave his mind.

With some trepidation, he felt around his teeth with his tongue, and he felt fangs. His heart almost stopped. With a desperate hope that he was just being silly, he flexed the fingers and claws shot out from his nails. His brain felt woozy and lightheaded, denial coursing through his mind.

'It was just a nightmare. I'm just confused.' He sat up in his sleeping bag, and examined his finger. The sharp claws were undeniably real. His eyes darted around him, perhaps this was just another dream, if he could just find something that could allow him to believe that, then he wouldn't be overwhelmed by his panic.

This was reality, and he was now a True Ancestor.

Jaune jumped up and ran to the locker rooms, he had an Initiation to participate in after all. He desperately distracted himself from the sudden pangs of hunger, not wanting to think about what it was he was craving for. With each passing moment, it was harder to accept his new reality, so he just ran away from confronting it.

AN: Just an idea floating around that I wanted to put down in words. I'm a big fan of Fate and Tsukihime, and while I'm using the concept of the Moon and True Ancestor directly from them, my versions are not the exact same.

On a side note, I'm surprised no one else has done a crossover yet. I mean a shattered moon and the moon princess seems like an interesting thing to explore.

I'm a bit torn between tones, I do want to explore the psychological torment of resisting an impulse built into the core of a monster, and using unnatural powers for heroic means. A monster trying to remain human while striving to be a hero. However, I heckin love Neco Arc, and eye beams and nonsensical abilities, so humor sounds appealing.

Please leave a review about what kind of Vampire Jaune story you want to read, it'll greatly help me decide. Also, I'm not sold on the current title, so it might change, recommendations welcome.