Mordekaiser main since release, my thoughts on changes.
Right now, regardless of how I feel about the strangle hold they put on his laning, I want to address my thoughts on his dueling potential as a bruiser, his presence throughout the game, and viability of build paths.
Mordekaiser's passive took a pretty massive hit. Not only was the 35% magic damage required to charge changed to 25% mixed, his damage output, outside of his q was also hit incredibly hard. Suggested build paths generally lean towards items that grant movespeed, health, slows and on hit effects like rylais, trinity force etc, the issue is, sacrificing any of the first 3 basically negates your ability to fight anyone with at least one dash or slow. You will be either kited into oblivion or nuked into the ground.
now, assuming you do end up finishing trinity, rylais and maybe a gunblade with some decent boots, you can finally start fighting people "effectively" but that is only assuming you are a lot more ahead of your opponent. Those are 4 of the priciest items in the game and you basically need every one of them to stick to an opponent, who has to have less items or be under leveled to lose. Even with 4 full items, if you fight on even ground, considering the current meta and the overloaded mobility of the past 20 champions released, your suitability is atrocious. This leads me to his power allocation.
It is an unarguable fact that his e was nerfed. What was once a 650 range spammable great source of damage, making it an amazing battery for your shield has been turned into a gimmick to apply rylais slow onto the opponent, hoping you can land your first of 3 q's and trying to keep up. Now, at this point, with morde's trademark horrendous attack speed, you have to land, not one, but two more to get any real damage on the enemy as the first two hits are nearly negligible. If however you do manage to land that third q, the enemy can kiss his health bar goodbye, building tanky, i have still managed to hit for over 75% of the enemy's health by flashing onto them for the third q, it does such an incredible amount of damage that your entire goal of the game becomes predicting the engage of a team fight to time your first two autos and nuke whoever gets close with your third, before e/ulting whoever you can and getting the hell out.
This leads me to build paths. The suggested build, is a trench of all trades. Does poorly at all and is a master of none. The damage outside melee range, understanding that e scales off both ap and ad, is not enough to initiate a fight and is barely viable as poke(ty based trinity force), the recommended trinity farce(not typo) offers a wide variety of skills greatly suited for many champions but the only point in building it on mordekaiser, assuming you aren't ahead, is to power up the first and maybe third q hit by timing your e right and sticking to targets. The item is far too expensive for how situational and perfect the circumstances have to be to make use of it beyond ~30 minutes. Overall, the suggested build path is good if you snowball enough to end the game by 20-25 minutes. It gives you a decent power spike and does a good job of helping stick to the enemy. Now, assume you get destroyed in lane by alistar cait, you get rylais and maybe start building some armour and a phage in case you get lucky and to keep cait from demolishing you/ali from pulverizing your hopes and dreams into the ground but it doesn't help, all your power is on your q, your e doesn't even clear the wave pushing your tower from a safe distance and you cant w onto a minion anymore, even under tower, you will have to sit and watch yourself lose the game.
Considering the late game overcooked oatmeal the recommended build turns you in to, i decided to try something else. I decided to run both full AD and full AP to see how they would work out, full AD wasn't bad but it was more of a novelty build, it would never be viable enough to try seriously but the AP build worked incredibly well. I rushed a revolver, then a rylais, finished sorc's and ran a nashors. The playstyle is completely different, you basically have to wait for the enemy to engage, look for the closest target, e and get your q off as fast as possible, it plays into the unhealthy q damage you already have but hey, if you're going to abuse it, may as well do it right. It's a simple fact of life that as he is, mordekaiser is too squishy to take the front line let alone initiate but the damage is there if you can figure out how to apply it. When death cap was finished, the third hit on q was dishing out 1900 damage on the 4.2k hp enemy vladimir, he died before I hit him with my e. As stupid as it sounds, Nashors is an incredible item on him right now. The best way to play him is still full AP, the only change is that now you need attack speed as well and your ability to fight multiple people late game has decreased drastically.
Anyhow, to wrap things up, The scaling on E is alright but the base stats need to be ramped up a lot if it's to be of any use on the hybrid monster you guys are aiming for. W could do with either a bit more damage to help shield up or give back the armour and magic resist buff. I am not happy with being forced into one lane with no room for creativity but i don't think this will ever change (self cast would be nice, i want to try jungle morde). the first hit on q needs a buff and the third needs a nerf, far too bursty and inconsistent/situational when i feel the aim was sustained damage, the shield becomes virtually useless, charge it up once and either q kills the enemy or you die.
All the testing was done with friends ranging from platinum-masters.