I mean, my biggest issue with the Nasuverse is that, while it's not that hard to get into on a surface level- it's a relentless bitch and a half to really, really have to dig into the background stuff to figure shit out because they scatter details across a variety of different mediums and obscure places. Just as a fun fact- anyone here know about Olga Marie? Y'know, current FGO main antagonist called the Alien God, died at the start of Singularity F after getting tossed by Flauros into Chaldeas-
You'd think that if you just dug through the FGO side materials and FGO itself, you'd know everything you'd need to know, right? Maybe going through Lord El-Melloi Case Files a bit, since she also appears there occasionally. That should be everything about the character there, right? Surely there's not some secret materials hidden away somewhere.
No, you don't and yes, there's always secrets hidden. That's because, you see, like a complete casual, you probably haven't read the fourth spin-off manga of the fighting game. You probably haven't read the translated version of the first opening song from the fourth year of the mobile game. You probably haven't read the physical guidebook of the anime spin-off of the mobile game. And you definitely haven't dug through specially released profiles that came with the anime taking place in an alternative universe featuring a different version of the character that has implications for this version or the other version from that fourteen-year old magazine.
This isn't hyperbole, by the way. Olga Marie appears across all of those. Nasu just decides to fucking leave his shit explaining everything over literally everything in the Nasuverse- including magazines that aren't even part of the Nasuverse properly or his blog that two and a half people know about most of the time.