regarding variants...

Done.

Is there a way to check if anywhere on the wiki doesn't have Guardians of Avon#Grim Reaper and stuff without going through individual pages or searching?

You can click "what links here" in the toolbox at the bottom of the sidebar. The search thing can probably do it too.

Edit: But it would be easier to just have ask an admin to use textreplace to change that to the new anchor on the new page.