I feel like more is okay.
He feels good to play, the mace feels heavy, he's always useful due to his ultimate. His laning requires good awareness due to lack of mobility.
He sits at a healthy 49.6 winrate, with 4% play rate. He has clear weaknesses and strengths, dodging his E is fairly easy, and staying back when he hit's W causes his shield to always be 50% effective.
His passive requires 3 hits level 1-3 it's not very good since it's hard to get these hits without taking abuse back. However with
it becomes amazing.
I think you should give him more time, who do you play against him? Are they sustain damage champions or on hit? He seems to excel against those, but heavy CC or life stealing champions give him a run for his money.
Dodging Mordes Q is very important and always remember you don't have to fight him in ult and QSS exist. Or even run cleanse!
Just some tips and my insight on the matter. I play the new morde a lot and on release he was broken, but now he's a lot more healthier.