Unpopular opinion - Grievous Wounds is an unhealthy mechanic.

When QSS wasn't able to remove Zed, Trundle and Fiora ults anymore people were furious at first. In the end though it turned out to be a really good investment to balance the affected champions in the future because previously, you had to give their ults tremendous power just because you had to keep QSS in mind. A single item countering out whole ultimates was a really unhealthy interaction so Riot got rid of it, with positive results.

And I would argue that with Mortal Reminder and Executioner's Calling it's pretty much the same. Granted, people rarely buy it around my MMR but if they do they just make a lot of abilities half as effective, for example Drain or ultimate and passive. While balancing these champions it's pretty much the same as with old QSS, you always have to keep in mind that the enemy will buy Executioner's Calling which means that you have to balance whole abilities around a 800 gold purchase which is just as unhealthy as old QSS was imo.