Does Ashes of the Just stack with other firebrands?

Hi! I just did a fractal run with another firebrand and I started wondering if Ashes of the Just stacked or it just replaces the previous/has no effect if the target already has the buff. Has someone tested it? Does it stack or 2 firebrands on the same group is not a good idea?

It doesn't stack. But it's just 2-3 stacks per person, which are consumed by any hit they deal, so realistically, they shouldn't last more than a second or two. Plus, you can see you allies' buffs if they already have some stacks of Ashes.