Counter effects on items should not be passives

This includes Grievous Wounds, Thorns and penetration stats, but I will be talking about Grievous since this is mostly a response to Repertoirs recent Twitter feed

You have completely rebalanced a huge chunk of fighters around having insane amounts of sustain rather than durability like they used to. Especially with juggernauts who often have no means of damage mitigation and are raw health bars with lots of sustain right now, Grievous can't possibly be made to feel "good" or strong after these champions invest so much of their build into it. Because if it did then it would likely be too strong.

Grievous Wounds is of course the reason that absurd sustain is necessary. It takes no skill to apply and its effects are basically permanent; in a fight against you this opponent loses 40% of their sustain defense. This issue only compounds in fights with more people. This is TOO STRONG for a passive; Grievous has been the far bigger balancing headache around healing than healing itself has.

You could easily balance Grievous by windowing its power to actives. Boom, now it doesn't do that, and the sustain champions have a window they can acknowledge where they will heal for greatly less if they fight you here. With that done, sustain can be tuned down enough so that Grievous actually has a noticeable impact when used well and that drain tank monsters don't become absolutely overwhelming if someone didn't buy it.

It is the same thing with penetration; armor is ridiculously abundant because of how much of it gets completely negated permanently and passively. Thorns can't ever be allowed to have a noticeable effect because it never has a downtime. Windowing these effects immediately relieves a lot of balancing pains.