Question on MOB becoming immune repeating using "Revenge"

If I use „Warrior->Revenge“ several times within a certain time-period on the same mob the mob becomes immune to „Revenge“ .. (displayed immune) … think he is then immune like 10-18 seconds or so…

Is there a Setting or Addon that would show me / warn me that the next use of Revenge would have no effect because the mob is currently/ still immune for that “style/ cast” ?

this is the german section of the forum, so please ask in German or ask in the US/UK forum

O.K. mache ich..