First, all of his existing weaknesses were exacerbated, but his old strengths were also nerfed.
His strengths were good all around AOE damage, and a good amount of innate tankiness. He lost 2 aoe spells and his 3rd spell was heavily nerfed, he gains less shield from the damage across all of his abilities (the ratio of damage->shield generation was reduced); the 2 things together actually massively exacerbate the issue of shield regen, as he is hitting fewer targets and generating less shield on a per-target basis. His damage is almost entirely single target focused now, but the slow rate of his auto attacks, combined with his reduced move speed make applying this damage quite difficult.
Certainly with old Mordekaiser, if I had
, I felt pretty tanky and did a respectable amount of damage. Perhaps I should try building towards that again at the start, because at least right now, building the recommended items I feel super squishy, especially early game.
Overall, he has a narrower range of impact, feels much squishier, and his damage is just much harder to apply overall.
Also, Teemo blind seems to stop all of his Q damage, which is quite disconcerting.