Fate/Extra is an RPG taking place in a world alternative to the canon Nasuverse where mana has disappeared from Earth somewhere in 70s. As a result, magecraft has died out and former magi families reinvented themselves as spiritual hackers, people capable of using their magic circuits to “digitize their souls” and enter virtual worlds wholly rather than interacting with them through an interface. It’s kinda unclear what they normally do with that ability aside from playing virtual LARP games as the game takes place in a very special setting that probably doesn’t have an analog on Earth.
Specifically, we find ourselves on the Moon. There is an ancient computer beneath the surface built by unknown hands. From the dawn of humanity it recorded all information about Earth from the movement of tectonic plates to lives of ameba to thoughts and ideal of every single person. Its purpose is unknown, but what is known is that it hosts a modified version of the Holy Grail War to which all spiritual hackers who can find their way in are invited. Hundreds of magi would fight in an elimination tournament, and the last one standing would get their wish, any wish granted.
You are one of these magi. Prepare to get flashed.