I think battlesuit cant be fused. I got cloud king finery by fusing two story three stars, infernal lord and roc god, and ruby plate by jackalope and flame summoner non plus, and by roc god and swamp shaman. Maybe, i have a theory. To get a mono, you should fuse one armor whit whatever element+ the one you want(say cloud king finery) and get the second armor that is whit weaker and stronger elements(jackalope water-earth). This is valid for my combinations... I dont know, maybe a coincidence...
But 3 on a streak?