The Epilogue Story

Hello! This is honestly my first time even using Reddit, so I really don’t know what I’m doing… but I was just really curious. I know the main story has roughly 856 chapters, and that the rest are side stories/epilogues. But the things I heard about them are really random. Things like how Yoojin is perceived as dead and has to marry 50 s-rankers. I really don’t know how this fits into the main story. Do the epilogues have actually anything to do with the ending of the main story? I mean, do I have to read them? I found chapters up to 870, but anything more than that is really hard to find an English translation of too.