One thing about kusoonna. "Kuso", which literally means "shit", is a generic derogatory suffix you can stick to everything. For example in anime you can easily hear "kusooyaji" or "kusogaki".
Now that I think about it, IIRC Apollo used it. Sirius was "kusoouji". Silvia was generally "bakahime", but sometimes even "kusohime". I think Apollo once called even Fudo "kusooyaji". Possibly it's a throwback
