The grievous wounds functional revert is needed but Mortal reminder will need to be changed

Reducing healing by 40% because of any physical damage is too simple and easy of a reward for getting this item.

Make Executioners calling build out of a pickaxe, increase the cost to 1200 (pickaxe 875 + 325g) and change the passive to an active that makes all physical damage in the next 4 seconds apply grievous wounds that lasts on the target for 2 seconds. 90 second cooldown

Then make Mortal reminder have 50 base AD the bonus armor pen and make it have a better version of the listed Executioners calling active that makes all physical damage for the next 5 seconds apply grievous wounds that lasts on the target for 3 seconds. 75 second cooldown.

It will still be effective and this also more clearly defines mortal reminder as the better option against squishy targets given the higher base AD.

And it will not make healers completely worthless but give a window of countering their power.