A question about Blood Magic

Hello :)!!
I have a question about BM. My character use it (as Keystone, not gem). At the moment I have 40% less mana reserved node and other reduced mana nodes for a total of 20%. So my total mana reserved should be 60% less. So, doing the 60% (reduction of mana reserved) of 60% (cost of the aura)i obtain 36%. That's means that the cost of my aura should be 24% (60-36). But, instead, the cost is 29%. Why?? What's that 5% more life spent?

And another question: using some other nodes that are part of my build (in the next levels), i'll reach the 81% less mana reserved. But if i use this shield http://pathofexile.gamepedia.com/Prism_Guardian , and i put in 3 auras, the mana reduced will be about 106%. Is that means that I can have 3 TOTALLY FREE auras?? Is it possible?

I don't know if this question is stupid because I am not really expert in this game. Serious answer will be apreciate :)!!

Thanks a lot :)!!

It would be 0.6 * (1-0.2) * 0.6, so 28.8%.

The "Less Mana Reserved" Node behind BM is a multiplicative Multiplier, the key word being "Less" or "More." The Reduced Mana Reserved nodes are additive Multipliers, the key word being "Reduced" or "Increased." All additive are added and multiplied to the total, whereas all multiplicative Multipliers are multiplied separately.

Also, the Reduced Mana Support Gem is it's separate Multiplier. So if you were to use a Level 20 Reduced Mana Gem (0.71 Multiplier) linked to your Aura, it'd then Reserve 20.4% of your Life.

Example:
Aura Base * Less Node (1 - 0.4) * (1 - Reduced Nodes) * Reduced Mana Gem
Or 0.6 * 0.6 * 0.8 * 0.71

Ahhhh undestrand :)!!Thx a lot man!! Now i've understand why of that cost.. So also using Prism guardian i can get just 0.6*(1-0.41-0.25)*0.6 12% as cost of an aura right?? Thx a lot man :)!!

"

Corsal8 wrote:

Ahhhh undestrand :)!!Thx a lot man!! Now i've understand why of that cost.. So also using Prism guardian i can get just 0.6*(1-0.41-0.25)*0.6 12% as cost of an aura right?? Thx a lot man :)!!

Np. And with Prism Guardian, it'd be 19.8%, or 14% with Reduced Mana Support Gem.

Do note, that this is for 60% Auras, 40% Auras would be about ~2/3 of that.

"

Sheriff_K wrote:

"

Corsal8 wrote:

Ahhhh undestrand :)!!Thx a lot man!! Now i've understand why of that cost.. So also using Prism guardian i can get just 0.6*(1-0.41-0.25)*0.6 12% as cost of an aura right?? Thx a lot man :)!!

Np. And with Prism Guardian, it'd be 19.8%, or 14% with Reduced Mana Support Gem.

Do note, that this is for 60% Auras, 40% Auras would be about ~2/3 of that.

Yes. Really really thanks. Didn't know about the real meaning of "More", "Less", "Increased" and "Reduced". Not it's all much more easy to understand :)!! Thx a lot :)!!