OK, I have a version of the Mod up at my website:http://tommyboymeshes.freedomforceforever.com/MUA%20Stuff.html
PLEASE READ THE INSTRUCTIONS BEFORE INSTALLING.
PLEASE BACK UP ANY FILES THAT WILL BE REPLACED.
It should add Quicksilver, Scarlet Witch, Vision, Beast, Giant Man, Hulk, and some extra bonus skins and meshes.
This is a beta version, and as such may have errors, some I know about some I may may be unaware of. If you find an error, post 'em here I guess.
If you haven't been able to install other Mods, then you won't be able to install this either, despite it being incredibly simple.