DVA
The DVA System, or the Dimensional Variance Accelerator, was SEBEC's most dangerous, most guarded, and most powerful weapon. The system was developed primarily through the efforts of Dr. Nikolai and Dr. Sonomura under the instruction of Takahisa Kandori and only two of those knew what the system really did and the requirements for it to function at all.
Maki Sonomura, a young woman going to St. Hermelin Highschool, served as a kind of power source for the system but also, subconciously, is the mind that directs it but the system itself creates a place whether it be a city or a building or a pocket dimension that is wholly influenced by her subconcious and thoughts. However, inside any mind there are shadows, and use of the DVA system has a tendency to let them loose in the confined area. The system isn't entirely reliable and more than one scientist has been putting on Kandori's chopping block for misusing the device--or trying to tell Kandori not to misuse it himself.
In the simplest terms, using the DVA system creates a TV Dungeon in the real world. It is fully functional within the Dark Hour and the TV Dungeons but there are reports of 'leakage' of the Dark Hour into the space created by the DVA System and, similarly, using it in a TV Dungeon is eerily easy.
In less simple terms, the DVA System is capable of creating and breaching dimensional barriers based on the capabilities and resonances of the being guiding the core of the system. The dimensional spaces invoked using the DVA system can be wide-ranging and complex, limited only by the person within the core. The vast majority of the time, this has been Maki Sonomura, but she was not the first... Nor could she be the last. The talents and requirements to be an effective core for the DVA system are not common, however, making the potential field of subjects fairly rare.
The DVA System is a powerful tool, capable of wide-ranging consequences for the reality we all know and beyond. Those who use it lightly will quickly learn their folly.
Or they would have, until Shirou Sekigawa, during an assault upon the SEBEC building, stabbed it with a spear. The resulting dimensional fissure created the now-permanent reality tear known as Mikage-Cho, sparking the entire Lunarvale Incident and almost causing fiery nuclear death. This did not happen as the incident resolved eventually, the DVA lost, and later its core removed during an assault by NWO operatives. This core was taken by demons and used to sustain them in the human world, a phenomenon which led to the Frost Junes occurrences and eventually, along with the Kotodama Effect, led to the colonization of the Inaba Mine Tunnels by myriad demons - more and more being drawn by the rich deposits of MA-347 contained therein.
