Basically you own your character, it was your idea to make them and they are your baby, as are any descendants or custom proficiencies, etc. However I own the character, if you publish it ‘publicly’ on my website, and I immediately make it public domain (normally a character shouldn’t be viewable by anyone except you, [your ref, if you ain’t one] and me) – public Characters have special scrutiny and I can delete inappropriate character’s that clutter up my database (I’m talking to you spam bots, no posting links to your sales pages or anything like that). You may upload character images, and link to external resources, but again Characters may be deleted if they are deemed inappropriate.
Honestly, this is meant to be a role-playing resource not a way to leave ‘buy cheap stuff’ spam on my website.
Your characters and descendants belong to you, but if you make them public then they belong to me and I’m sticking them straight in the public domain. This means that any user generated content shared on the site is shared, and anyone can use it in their games.