Time Travel

Spiritron record anchoring band[1].
A Quantum Timelock is a metaphysical event, it calculates the average “value” of each parallel world’s events, then locks past events down. A phenomenon that separates what was, and is, from what might be.
Our universe allows for countless possibilities and creates many parallels worlds and histories with different developments.
The universe has a finite amount of energy to spend maintaining each parallel world. Because the universe itself would expire if these realities were to expand without limit, it conserves energy by, excising worlds, at specific intervals, that have veered too far from the strongest, most stable timelines.
The Moon Cell has concluded that the universe we perceive of, which should be unstable, is being stabilized across the present, past, and future by this culling process and by quantum time locks.
The easiest way to visualize the process is to envision time as a giant tree, one that would grow indefinitely if left alone. The excision process is comparable to trimming the unneeded branches and leaving only the trunk of that tree.
History that becomes a part of the “time lock”2 will not change, even if it is affected by the past and future. The incidents that occur during a time lock will, in fact, never change, no matter what happens.
Even if one were to go back in time before the time lock to try and change history, once one reached the time lock, history would be forcefully restored to what was already registered there.
In a universe with quantum time locks, the outcome that is registered in an quantum time lock will not change. A time traveler can only alter the “process” by which it happens, but never the “result.”
For example, imagine that there was a war in Britain, and that the “result” that was locked in afterwards was that Britain was destroyed.
Even if you could manage to travel back in time and affect history so that Britain flourished, the war ended peacefully, and everyone had a happy ending… the moment that history reached the time lock, it would cause whatever “corrections” were necessary to ensure that, despite your efforts, Britain was still destroyed.
You might be able to change the lives of one, two, or perhaps even a handful of people, but you could not change the course of the vast river of human history.
That is the “Quantum Time Lock,” also known as the “Foundation of Human Order” in the world of magecraft.
On the other hand, it could be possible to deny human history from its foundations by destroying a quantum time lock through some great feat. But even with that method the most that could be done is deny human history beyond the destroyed quantum time lock.
The ones who can determine the next coming quantum time lock are those living in the era. Past and future intervention cannot affect the quantum time lock.
Archimedes’ goal in this game is to completely destroy the Moon Cell before the next quantum time lock, leading to a base world that would start from that precondition.
While it is normally not something that could happen, to do that Archimedes continued to shift across worlds.
If Archimedes were to completely shut down the Moon Cell before the setting of the next quantum time lock from his subjective perspective, he would achieve victory.
Although Archimedes emerges victorious on several occasions, he is not able to destroy the Moon Cell in any timeline.
While Archimedes was endeavoring to bring his plans to fruition, the Main Character was able to prove proved the route of a world that was average yet with the most potential to grow, and the quantum time lock was decided.
And just like that, Archimedes’ plans went up in smoke.
By the way, the timeline where the Main Character entered the titan’s cavern with Archimedes and was split into several pieces (right after the start of the main story of EXTELLA) is listed as “Quantum Time Lock A,” while the True Nero route ending is “Quantum Time Lock B.”
No matter what Archimedes does within this timeframe, the final “result” has already been determined.

[1]In the book, the term is printed as 霊子記録固定帯, however in-game (both Extella and FGO) 量子記録固定帯 is used. It is likely that 霊子 (spiritron) instead of 量子 (quantum) in the context of quantum timelock is a typo.

Rayshift [Other]
A movement method that transforms matter into Pseudo-Spiritrons, and transfers it to arbitrary coordinates.
A time leap technique that has been put into practical use with the cooperation of the Atlas Institute.
While claiming to dispatch the Master to different eras through Spiritron transfer, in reality it’s a method to where they are “projected and observed” after having become Spiritron data. Its realization was regarded as dangerous by the Mage’s Association since it can be used like a time machine.
Its completion was criticized as impossible because theories aside, the technology could not catch up, but Marisbury, representing a research facility of the Quantum Mechanics department, invested a huge amount of money and negotiated with the American government, received a supply of materials and engineers, and finally managed to complete it. The experiment is subject to the permission of the United Nations (although mostly to the Mage’s Association). The time of the investigation of Singularity F was also the first use of Rayshift.
A magical accelerator rather than a quantum accelerator was installed around the walls of the outer periphery of Chaldea, and it was supposed to be spun at maximum output to convert 48 Masters into Spiritrons and Rayshift them, but……
(Conversion of one Master with a compact accelerator is also possible)

The Rayshifting process:

1. Entrance into the Coffin. Examination and definition of every parameter of the Master candidate.
   
2. Creation through magecraft of a “Living but Dead Box”. Placement of the Master’ existence into an “unknown” state.
   
3. Beginning of separation into Pseudo-Spiritrons. A supercomputer is fully mobilized to calculate the deviation of history and causality caused by the absence of the Master, their body and fate, and to apply a provisional numerical formula to correct history properly. It consumes a huge amount of electricity and magical power, but that’s covered by the accelerator.
   
4. Usage of the data from the human history map CHALDEAS, which are guaranteed up to 100 years ago, and confirmation of the status of the destination of the Rayshift. Beginning of Spiritron projection.
   
5. Complete isolation of the Coffin and the outside world once all the Spiritrons of the master have fully been projected in the destination of the Rayshift. The inside of the Coffin will be defined as nothing.
   
6. The Master will materialize in the era of the Rayshift. Usually falling from the sky.
   

End.

Hourglass [Mystic Code?]
The hourglass that became the means by which Kanata was transported from modern times to the past war times. Usually, time travel is a miracle that can only be performed through the mysterious art known as True Magic, different from Magecraft, and it is currently unknown whether the phenomenon in which Kanata found himself is actually that.