Quote Originally Posted by Gabzor89 View Post
Previously thought the message only appeared when people tried to fuse mono earth and mono air. Now I shall go think about the implications...
I guess Cloudking + Mono Earth = not allowed (doing so with Corvus would guarantee Cloudking)
Ruby Plate + Mono Spirit = not allowed (doing so with Wanderer Shroud would give Ruby Plate)

At least this should confirm you will not get the armours you put in.