I would not deny that the elimination methods were your writing, and that your setting allowed us to create the characters. You are ultimately a great admin, writer, and roleplayer, and you came up with those. But the characters ultimately are our creations that we have the rights to, a property we own, and it did not become yours. Unless you are saying that by joining your roleplay, what we made is now your property--which I hope you are logical enough to think that is not true---using our characters, settings, backgrounds, and including them without our permission is considered copyright infringement, because even with proper credits you are using something from other people that you are not given the rights to use in your own creation.
If you actually (to my surprise) think you own our characters----I'm glad you are willing to admit that what happened is your fault. And admitting it also means to give back what was never yours.
Please remove our OCs' names, background, setting, and anything that you know we created from your Elimination Methods. Keep what is yours, yours, and erase anything that's not yours. You are free to write up anything else in place of them. That's really all what we're asking for. Maybe even think of it as a way to show some respect after what happened. We do have the ownership to them, after all.
None of us like to drag this out, neither come in contact with you again. We wanted it to stay as a past drama, I'm sure you do too. So please do as we have asked for, as you have nothing to lose from it either. Thank you, again!