Any possible continuation of the Anime with stuff from the Mangas/light novels?

So, im currently rewatching the Anime the second time and I really love it but at the same time I am kinda sad because i've heard about the mangas and light novels telling so much interesting story but to be honest i dont really like this sort of stuff because they are kinda difficult to read for me and most of those ive seen are really missing color which i also dont like. But, i've heard something about a 3rd season with some sort of >!Aliens ?!<, but nothing tangible. So, i would really like an anime adoption of the Mangas and light novel, because i dont really think Aliens would fit into the whole story. So, if anyone can tell me something tangible, i'd be really apprechiative.