Controversial opinion: DON'T nerf Mordekaiser yet
We've got an Illaoi situation on our hands again where it feels more like people don't know how to play against a champion and instantly demand nerfs.
Mordekaiser has a very easy learning curve and is probably almost as easy to pick up as a Garen is, meaning we're rapidly seeing optimized play with him.
The problem is, nobody is respecting his Juggernaut levels of damage, choosing to approach him in a head on fight and getting destroyed over and over again. If people were to respect his Q and E, the way they respect Darius's Q and E, we wouldn't have as bad a problem with him as we do now.
Tl;dr, he may be strong but stop feeding him and you're good.
as an example is the worst possible thing you could of done if you want to say not to nerf him. Illaoi got changed so she is easier to deal with(aka nerfed).