You see, all those comments and people still don't get that no...You literally do not know why she is doing what she is doing. Nothing is telling you that she is trying to redeem herself for anything she could've done. As I have said a whopping 2 years ago, she could literally just be bribing him or trying to buy him and that wouldn't exactly make her actions good. Now of course I do know why she is doing it since i am the author, but given how little i have written about this mother, i cannot just tell you ' she is like that, trust me' . You need proof to affirm something. And here, with the proofs that are present, you can only say that at worst the mc is basically antipathic and barely cares about his mother's attempt to do whatever she is doing. He could be an asshole as she is trying to redeem herself, or he could be emotionless as he ignores her attempt at buying him. You can only work with what you have, and what you do have is very little.
The webcomic has been over for years, I knew saitama was not blast, many people did. This is simply a fanfiction, hence as with all fanfictions it can and will change the canon story