Originally Posted by
AvengerEmiya
But you see, that's the plot twist FGO is leading up to. The protagonist really is ten years old, and the teenagers we've been seeing are just delusions created in Matthew Kyrielight's head. This whole time Matthew's had a shota/lolicon fetish, but she stays in denial of it; constantly calling the protagonist "senpai" to fool herself into thinking she's younger than they are.
Fate/Grand Order's story is really about Shielder coming to the realization that she's a pervert.