So, can we address some of Morde's unhealthy aspects before even considering tinkering with him?
A lot of suggestions regarding Morde were just adding stuff to him without really compensating for the added power. Mordekaiser has been a very difficult champion to balance because of his Passive and to some extent his ultimate.
His laning phase in particular can be extremely oppressive like pre-rework darius and Garen to some extent while his own rework didn't really tackled these kinds of game health issues.
So, before we just add to his numbers and such we have to consider revising his passive interaction to really try making Mordekaiser more satisfying and fairer for both the Morde player and his vict...erm....opponents.
He could definitely profit from some low-scope changes to fix his lack of interaction during the laning phase but also giving Morde other ways to succeed other than just dominating lane and then snowballing a lead or just completely fall short after it.
My personal suggestion would be weakening the shield gained from minions if not outright removing them in favor of maybe increased shield generation of enemy champions and actually juggernaut base stats.
Another wonky Idea was giving his E a small implosion effect and changing it to vector casting. Outwards: Small knock back Inwards; Small pull (maybe 100 units or so)
Still, the fact remains, if Morde needs buffs Riot should just invest some extra time in changing more than just basic numbers in his kit. Just look at the Urgot changes, they actually shifted numbers AND added stuff instead of just giving him simple buffs
Mordekaiser
but there is so much stun and knocks in the game she isnt as fun to play anymore