We all have headcanon right? Things that weren't quite covered in canon, or weren't covered sufficiently, or were never even touched on at all and so you have to speculate and extrapolate and all those other fun -ates.
Anyway, the way this works is that you post with your characters and other people ask you questions. About your characters opinions about something, what happened during such and such a time that canon oh so helpfully skipped over. Feel free to make your questions and answers as long and probing as you want so we can all find out a bit more about your characters.
Oh, and I know we're all cool and chill adults, so I shouldn't have to say this, but no bashing on another person's headcanon. And no acting as though your headcanon is actual canon.