Responses
I don't think it's manga. Is it a manhwa?
Perhaps, it is:
https://www.mangago.zone/read-manga/beyond_memories/
Yes yes thos is it.
I was reading a Manga like a few.months back and I don't remember the name. So it's BL and the MC I think is an omega who is supposed to be married off to this alpha. And he's reborn....but just doesn't know that. The alpha seems nice at first but the flash backs start coming in to show how much of a bastard he truly is. That's all I remember.