Reduced mana reservation

On auras, if I put points into the 5% reduced mana reservation, does that bring it from 40% -> 35%, or 40% -> 38%.

Also, does 10% reduced mana cost of skills have any effect on auras?


My build (not great I know). Trying to work towards a tanky / aura companion to my blood frenzied dual wield dps partner.

http://www.pathofexile.com/passive-skill-tree/AAAAAgUBAecCcQSzBVsTWxRNFy8ZLhoyGjgaVSftKS4pTy3SMHUyCTKJNug62EZpRtdN2E99UWBUSVWpVdZXDVfiWK9Z813GXz9gbWCIYVJko2TnZp5nm3C7cql35XzZfVOAVoKbgziExIuMjHaQVZHOl7SazJ2Ans2fy6IApzCnhKmVrKqsurT5toa53cAaxBXE9tIh1I_ZYd3z4XPh2udS7DjtIO8O73zwH_Iv89322g==

38%