Ith rune on armor don't seems to work [SOLVED]

15% Damage Taken Goes to Mana

For me that mean if i take a hit with 100 damage, 15 must go to mana and 85 to the life.

Is it not right?

So let says i have 50% Damage Taken Goes to Mana, if i take a 1000 damage hit, i need to loose 500 life and 500 mana? Correct?