For a brief period of time, there was a userstyle making the rounds at https://uncyclopedia.wikia.com/User:Llwy-ar-lawr/fakevector2.css that adds Vector skin support to Wikia. It was originally designed for the Uncyclopedia spoon, but is mostly compatible with all wikis. Since the Uncyclopedia spoon has been shut down by the Wikia admins, I have copied the CSS to https://community.wikia.com/wiki/User:Pythoncoder/global.css. I will make a few updates soon for greater cross-wiki compatibility. Posting this here because people who previously used Monobook may be interested in something closer to Monobook than the most prevalent present solution (PseudoMonobook).