Reworking Mordekaiser to a playable state
Mordekaiser has been plagued with bugs and a kit that does not accomplish very much unless tuned to give him an experience advantage. The entore kit revolves around using health to build shield and be a frontline juggernaut. I think with the updated mana items he would be vastly improved with a rework and change to how his character functions.
First Mordekaiser is a manaless champion, but most of the great AP items give mana. Vladimir has seen success, but he has much more inherent sustain and evasiveness in his kit. Adding mana to Mordekaiser's kit would be a better avenue to balance his abilities and scalings.
The first part of this new kit revolves around reworking Mordekaiser's passive. Instead of scaling off the damage he does, it scales off his AP and Mana, so he can reliably gain tankiness. It incentives him to build mana items, and buffers his health since he is not building full tank.
Passive (Iron Man): Each time Mordekaiser expends mana he gains a shield (Based on AP and Mana). After 2 seconds of being out of combat this decays away.
I have left his Q in tact, as it works well to deal consistent bursts of damage and be a threat.
First Ability (Mace of Spades) : Mordekaiser empowers his mace, and the next two strikes deal increased damage, and the third dealing massive damage (AP Scaling)
Mordekaiser's W is also a good ability to build around, but instead of healing it can provide a shield for him and his ally.
Second Ability (Harvester of Sorrows): Mordekaiser throws out a field of metal towards a nearby ally. When the fields touch they deal consistent magic damage to all enemies in the area. Mordekaiser can recast the ability to break the field and provide both targets a shield (Based no AP and Mana)
Mordekaiser's E is not a fun or powerful ability to play around. It's short range and low utility make it fairly underwhelming. As a tool to help Mordekaiser feel like more than a walking suit of armor. His new E acts as limited ranged crowd control and poke, but at a significant cost to Mordekaiser.
Third Ability (Siphon of Destruction): Mordekaiser throws his mace to a location up to 800 units away. All enemies hit suffer a 50% slow. Mordekaiser can recast this ability to pull his mace back to him and drag enemies slightly closer to him that are caught in the backlash. Mordekaiser can not auto attack while he does not have his mace. (Based on AP)
The first cast acts much like an Olaf axe, and slows enemies that it hits. Since Mordekaiser throws his mace, he can not auto attack while it is gone. Finally pulling it back to him has a Swain like effect of a minor pull, but not completely. 800 Range is a suggested distance, but can be tweaked.
Lastly Mordekaiser's ultimate is boring, and basically a health potion that gives you a pet if your team collapses on the correct opponent. It breaks Rylias and is a balance nightmare. And then the bugs. The new ultimate synergizes with this new vision of Mordekaiser being a frontline tank juggernaut that can lead his teammates.
Ultimate (Painkiller): Mordekaiser Targets an enemy champion and applies an 80% slow to them for 3-5 (Based on Level) seconds and all damage Mordekaiser deals to them is amplified by 10%-30% (Based on Level). For the next 3-5 seconds (Based n Level) all shields Mordekaiser receives are also applied to all teammates within 1000 Units of Mordekaiser. These shields start decaying instantly. (Debuff on enemy is named Hallowed be Thy Name)
Yes, this is somewhat designed with Seraph's Embrace in mind, which works well with the addition of mana and the scalings on mana. notably it provides a significant window where Mordekaiser is very powerful in a fight, but not always at the begining. Teammates are rewarded for standing near him, but champions with area of effect abilities get stronger.
This new Mordekaiser vision would be far better to balance around than the swingy nature of taking the soul of an enemy. While cool, it does not seem to translate well into the game. This new Mordekaiser lets him stand tall against the enemy and proactively protect his teammates.
TL;DR: Mordekaiser based on mana, Olaf Axe for E but different, and Shielding ultimate.