That is probably it, and I think Voldemort's push for power probably had quite a lot to do with the Gryffindor/Slytherin philosophy becoming as it is in Harry's day. Certainly, by fifth year, the Marauders seem to have come to the conclusion that people should be attacked just because they're a Slytherin, and that's when we know Voldemort was recruiting.

Sirius' mother reminds me of Bellatrix, actually, which makes me think there might have been some congenital issue thanks to generations of inbreeding. Phineas Nigellus, on the other hand, is alright - a bit of a bastard, but essentially good - and a lot of that can be put down to time period and social standing (Victorian upper class) and potential childhood trauma (older brother Sirius died at eight years old according to the Black family tree) as well as the kinds of situations we see him in (no one would be impressed if they were kept in Hermione's bag for a year).

I love Eternal Return. It's one of my favourites although it is fairly short. There's nothing really out there that explores things going wrong and getting progressively worse over a prolonged period. And yeah, no good Marauder time travel.

There is a kind of super-special-wealth aspect to a lot of the fics that deal with pureblood society, as if people have taken a look at how wealthy the Malfoys are and decided that that must be the ideal. The purebloods we know of, though, seem to be scattered across all branches of social class rather than exclusively aristocratic (as they are in fic) which wouldn't make any sense at all.

It's a tragedy. I loved it until it started giving me hives TT.TT I'll definitely seek you out, though, when I start working on them. There's a few other things I want to finish first (Genderswap Big Bang and Poetry_Fic challenge to name a couple) but I think I will actually try and go for it. Poetry_Fic is going to be about the Blacks, but more Phineas Nigellus rather than the recent generations.