No, it's not ethical. And they won't like you after that.
Interactions on online roleplay spaces are largely transactional. People are going to like you for whatever enjoyment you bring to their experience. And they will very quickly dislike you if you destroy their enjoyment. Giving them space for character development, giving them fun stuff to roleplay about, nice writing, making them feel good about themselves, et cetera -- versus getting in the way of their intended plots, disturbing their fun, triggering them, emotionally burdening them in an OOC way, delegitimizing their character concepts in your roleplay, et cetera. They don't usually care about you as a person in real life; at most they are just trying to act ethically themselves while pursuing the enjoyment of a hobby that we share.
If you make them feel bad, that's stuck in their head now. The most respectful thing to do, ethically, is just leave them alone. And if you can't do that, because it's a small hobby... don't bring back the bad feelings to them in any way. Just play quietly and politely. The most ethical way is to be clear about who you are so they can avoid you. The second most ethical way is at least to let the game runner know who you are. The third is to just turn over a new leaf without bringing any attention to it.
Insinuating yourself in others' good graces and then bringing back whatever bad feelings you once caused, in an effort to pad your ego in some imaginary redemption arc, is honestly kind of a very lame plan that will backfire. They will feel betrayed and annoyed. And those are bad feelings, so all you've done is make things worse, because now they have even more bad feelings on top of the old ones.
At least, this is my opinion based of my admittedly not-great understanding of human interactions and basic ethics of integrity.