Ok, with spirits the control entity is useful if you have them in a matrix or in your fetch, but what about corporeal species like a horse. For example, I want to control the horse of my enemy, prior to control, I send a spirit to reduce its mp's to 0, and I have an unconcius horse, ok? and, then I cast the control (horse) spirit spell and... I can command an unconcious horse, I don't think it is very useful, so I think there is anything else I don't know.