I already had dungeons libraries, though mine was missing some files for whatever reason, but the version you linked worked. It also required enchant with mob as well for some reason. But now I'm getting a different error, something about dungeons gear's files not registering properly?
Custom faces could be done with resource packs. As for the other stuff, my guess would be that he uses a combination of lots of players and a morph mod and some sort of custom NPC mod.