I feel his innate is too powerful. His old version of it was so much more balanced and used so much more brainpower. I dislike the fact that melee champions who are supposed to counter him cant because of his passive. Everything else for the most part is fine and balanced but his passive isn't and I believe that is what's making Mordekaiser a monster to deal with. Let me explain. Once he attacks you 3 times with his basic, his passive upgrades dealing a lot more AOE dmg, giving him more movement speed, and let's him refresh the passive every hit. Practically and theoretically, his passive can never wear off because his passive is set up in such a way that won't allow it to wear off.
Sure, you can do the hit and run style of gameplay but for a champion that builds no armor, a melee champ or bruiser should be able to square up with Morde when they pull up to him. Morde's other abilities surpass other melee champs and the fact that he's AP gives him the advantage of dealing a lot more damage than melee champs when he uses his abilities. His W does have a long cooldown but it acts as both a great trade tool and an escape tool since he can use it to pull towards or pull away. Once he hits 6, you're basically done for since he steals you're abilities.
Don't misunderstand me, I'm not saying his other abilities are overpowered. Nor am I saying that all melee champs are supposed to counter him. I'm just explaining why his passive gives him an unfair advantage over the champs that are supposed to counter him and gives him way more power and survivability against champions he's supposed to not do well against. Either his movement speed bonus from the passive or the refresh needs to go. It sucks and it's unfair trying to fight a Mordekaiser when his passives last for 10-15 seconds in a fight because he's gaining more MS than you allowing him to mow you down and continuosly refresh his passive. and that's not even factoring in the fact that he can build Rylei's Crystal to make matter worse. On the other hand, he's useless only being able to farm until his cooldowns wear off and he hits level 6. I suggest taking away his Darkness rise and giving him his old Q back except making it to where if you miss a Q, you can't execute the next Q in the sequence. It would allow him to still trade in fights and do damage while taking away his oppressiveness in fights.