Just some kind of crutch until his VGU
His kit's pretty solid but he relies too heavily on Rylais, giving him a replacement and calling it a day would be the easiest way to go about balancing the item without having to care about dumpstering ONE champion. A quick and easy bandaid
MM and Rylais is turning into HateDaddy-levels of posting
won't function well without 
with all the massive MS boosts worming its way into the meta.
This is a great idea
When they made Athene's into a support item they compensated Galio by giving him MR per level.
I imagine it will be about that level of adjustment for Mordekaiser. Maybe some more base health.
I honestly doubt they'd do a fix like this. Viktor's unique item is his passive, and it's part of his identity. Even Rengar's Bonetooth Necklace was lost (though that had problems of its own).
You mean like Viktor's Hex Core?
That'd be cool.
Morde can be solved pretty easy:
For morde itself, why don't we rework him into a jungler? If you think about it he has a lot of elements to in hit last rework that kinda reflect to it. We can give him some interactions with smite on his ult like smiting red & blue enslaves them. We give his enslaved pets some kind of cc that allows him to gank with it.
I think the item would be facinating if it is not a AP item, but some sort of defensive tank armor item, that compensates his bad numbers.
