For her most part, most Onikages don't like other kages, especially kamikages. Many Onikages also like other Onikages however. All kamikages usually respect other kages, but a good number of them even see other kamikages as allies. 

Things you should know about Kage's work (thanks for mentioning this, I'm going to be completely revamping the OOC today with refreshed lore and everything):

When binding, they tear up the soul of an organism with small spirit reserves, completely breaking it apart. Then they meld their spirit between the shattered host's spirit and fuse it all together to create one, amped up soul. The kage lives as spirit and exists within your soul. You can hear it, and B'a case she can even see it, but only you. Other people cannot hear or see your kage unless it is a phantom. A Phantom is the term used to refer to host's whose Kage's have COMPLETELY taken control of them, overpowering their will completely. This means it's literally just a human body with a Kage's will. The Kage's voice is heard through the body.

Furthermore, as for kage relations, that's highly player dependent. Kages can be seen as a separate plane of npc's, and it's completely player driven. For example Yugeto already DISCUSSED his kage being affiliated with someone else. He asked that person "hey what if our kages knew each other" and that's pretty much it. Before humans, they lived on aeros like any other intelligent civilized species. There were fathers, mothers, sisters, brothers, etc. And although 99.9% of their existence is an enigma, that basic concept of relationships) that seems somewhat universal to all life) is known to be true for them.