Direct Feedback System
Keyword
AXZ Episode 5[1][2]
Developed by a team led by Dr. Ver, this is a device that enables direct interference into the human brain.
Unlike other countries (mainly Japan), America applied its relic research mechanically and used heretical technology to develop things such as the "Air Carrier" helicopter that was equipped with "Wizardry Stealth" and the "Remover Ray."
The Direct Feedback System is also one of the fruits of their research.
It was once cruelly used to warp the emotions of Kohinata Miku and force her to don the Shenshoujing Symphogear.
After the end of the Frontier Incident, many items were gathered as evidence, and the Direct Feedback System was one of them.
XV Episode 5[3]
One of the technological legacies of the FIS recovered as evidence after the Frontier Incident.
Developed by a team led by Dr. Ver, this is a device that enables direct interference into the human brain.
Later, Elfnein used alchemy to convert it into an (in)complete device that allows the observation of the brain called an "electric field microscope."
The device is named after "Beatrice" from "The Divine Comedy" by Italian poet Dante.
Just as the protagonist (Dante himself) met her in hell, the observer must also enter and travel through a "dangerous world," the subject's virtual consciousness.
Another reason for the name is that the root of "Beatrice" (Viatrix) comes from the Latin "viare" which means "to travel."
As can be seen in the opening animation, Elfnein spends a significant portion of her own free time off-duty using the device.
Although Elfnein sees it as a very important and engaging activity, Hibiki does not understand this and judged it as "just work or something."
XV Episode 9
Kazanari Fudou had attempted to tame the newly revived Shem-Ha into an instrument of the national defense, but as one might have expected, that was not possible.
What was carried out in attempt of that plan was not control over the god itself, but control over a girl who would serve as the vessel for that god.
In a massive server room beneath the Kazanari Estate, control over the mind of Kohinata Miku was gradually being established.
The completion of that process should have led to the the birth of a new divine weapon ― the next generation in deterrence.
