Tldr;
The first story (the tragic one) is the first premise.
The second story (where blonde MC got pregnant) is their second life, where MC was the only one who remembers what happened in the past (first story).
This new season, the third story, is an alternate story, where this time only the ML (brown hair) remembers what happened in the past (first story).
But again, as mentioned in the first page of the chapter, this third story doesn’t reflect what happened with the first story; in others words, this is not a Sequel, but rather an AU: Regression.

Sorry I'm so confused. I'm pretty sure it's me but what is going on??!! The guy that got pregnant like four times died and then (I THINK) we go to the past is he alive or not??? Wtf is going on and why is everyone fluent in gibberish?? This story is so confusing to me? Does dead guy with kids never get justice?? Like that's it ? SOMEONE.HELP this is not a mean comment I'm just so confused