Hi everyone

For the past week i've been watching neon genesis evangelion ( original anime ) and I'm really enjoying it, but there are some stuff that I don't understand like the s2 engine which is mentioned but never explained ( I'm not sure ) and because of that i searched for answers on EvaGeeks ( awesome site by the way, I've never seen a community as dedicated to an anime ) and i noticed that there are elements of the lore that are never mentioned like the first ancestral race and i wanted to know where did these pieces of lore come from ? Or were those elements mentioned in the anime that I didn't notice because of my own stupidity ?

There is a secondary source of more-or-less canon information, the "Classified Information" in the game Neon Genesis Evangelion 2.
Read here.

The lore comes from the game in general -- for examples, see the various endings plus the Rei and Kaworu's scenarios for which I've shared translations. The CI have the reputation of being the "lore source" but it's an oversimplification. I assume it's mostly because it's a game feature specifically designed to be a collection of info files, so it attracts more attention than the surrounding game context which confers additional, often necessary, information. Once upon a time, it was easy to find a transcription of the CI in Japanese; but when the rest of the 'secrets' are buried inside a massive game script, you're on your own...

Thanks !