There's also an anime way less popular than Fate simply named "Gilgamesh" from 2003. I barely remember the plot after watching it a long time ago, but I do reme

There's also an anime way less popular than Fate simply named "Gilgamesh" from 2003. I barely remember the plot after watching it a long time ago, but I do remember that some several years before the events take place an event called "Twin X" knocked out all advanced electronics and prevents them from working. One moment that most stuck with me was when a character called "The Countess" later on reveals she has a massive skyscraper of vacuum tubes, that is able to function as a primitive supercomputer. The eponymous Gilgamesh of this one is actually split into 10 relatively forgettable characters, and the head researcher of their faction is called Enkidu or something like that. And their faction wants to wipe out most of the human race in some kind of mystical extinction event, to give rise to a superior humanity. It's a relatively common motive for the bad guys in Japanese media, I recall hearing the big bad gesticulate wildly about doing the same thing when I shelled out enough 100 yen coins with a buddy to clear the story of the "House of the Dead" on an arcade machine.