Hi guys, i test some skills to use at my sup barb. Currently I have done 116, almost done 117. I want ask about stacking of mutilation rune when using lamentation belt. This belt allow to stack rend twice on every mob. Does someone know is it only for damage calculation or it allow to stack 10% increased damage twice, then would be 20% or 21% depend how this is acumulated, additive or multiplicative. I know that rend rune is reaaly common with Istvan swords but i want to test it without this set (help to decrease coldown of skills with obsidian ring).