Wikia has been trialling new userpages for a while now. They're basically the same, but there is one technical difference that would affect the Skybrary: You will only be able to edit your own user page.
Skybrary users have been allowed to use any page in userspace they like, but the Skybrary is the only wiki I know of that allows it. Your userpage is meant for you to talk about yourself and provides a way to contact you; being able to share on topic stuff (e.g. character bios) is secondary.
I don't know if or when Wikia will activate the new userpages on older wikis, but here are some alternatives.
Subpages are a convenient way of sharing anything that's on topic and using them means that your account can be named whatever you like. Category sorting can be fixed with sortkeys.
- User:Kasarn is my own little portal with links to subpages and other wikis.
- User:Kasarn/Arikatas and User:Kasarn/Talia Balain are my character pages.
You could also register a sock puppet account. Sockpuppets are frowned upon, but only because most people use them for underhanded purposes. If you're upfront about it, there's rarely an issue.
The downside to this is that accounts are used across all of Wikia, so there's no guarantee that the username you want will be available.
My sockpuppet is User:Arikatas, but I already use subpages so I don't keep anything on that user page.
An administrative solution would be to request the creation of a custom namespace, such as PC: or Character: or whatever. Creating an additional namespace would mean that people wouldn't need to register at all.