[{quoted}](name=Baka Red,realm=EUNE,application-id=3ErqAdtq,discussion-id=wn72V7aE,comment-id=0005,timestamp=2017-06-06T10:57:55.890+0000)
I both agree and disagree with the OPs opinion. There needs to be some way to counter sustain tanks/life steal, but I consider current Executioner's Calling to be little too strong - at least in the parts of League I play in; namely Howling Abyss. I love playing ADCs and executioner is one of my early game tools if there is anyone who has good (or even moderate) sustain on the enemy team (Mundo, Warwick, Swain, Vladimir, Darius, Illaoi for example).
I think the main issue is that for 800 gold, Executioners calling does the same work as either Mortal Reminder, or Morrello's. Sure it might have a shorter duration, but it's just as effective at blocking sustain.
What they should do, is rework Grievous wounds to be numerically dynamic, and give Executioners only half the intensity. That way, you would have to build a lot deeper into a Grievous wounds item, if you really needed to counterbuild sustain.
That in mind, Mundo is kinda special case, because the majority of his tankyness comes from his sustain. But that's were I think you could put it special exceptions, on ones kit. (Perhaps if Mundo's ult on cast removed grievous wounds, and/or, reduced it's effectiveness for the duration)