I know how you feel.

When I was trying to Skill Trial my Hashirama [First Hokage] I spent roughly 200 and didn't get his mystery to +1 or Y+2. Meanwhile I got all his other breaks. So, since he was still unusable to me, I went ahead and tried again, about 100 Vials later, I got his Mystery and at the same time, got his Passive to be immune maxed out.