[@vancexentan]
Still poking around the water for potential can and can't do, so would a Guardian Spirit be okay in a master sheet? They wouldn't be able to easily manifest themselves (even for short periods) into material form, they'd just serve as a spiritual medium for my Master to base his magecraft around. 

This came from me planning on making an Eastern magus who focuses more on the spiritual side as they do. Just wanted to toss the idea forward and getting your thoughts before digging into it~