You are one of several very active admins on that wiki. You have the tools to deal with problematic users. And have done so since that linked user is blocked there.
There is nothing for anyone else to do, not even Staff.
Now, if that user starts to follow you to other wikis (aside from Central), then you can contact Fandom Staff with links to complain of cross-wiki harassment. Although it usually takes 2 or more other wikis and/or severity of the messaging, but even if denied, at least you also build an Incident trail with Staff.