Well I forgot about the "multi conditions"
Maybe choose the icon of the first condition automatically and let it change manually, or let the user choose if he wants to use the icon of 2nd, 3rd, 4th, ... condition as he adds a condiiton.
I bet most of the diplayed stuff will be related to only 1 buff (or result in the view of 1 desired buff where it's "all about", like your argent downbreaker icon)