When will mordekaiser get's all of his bugs fixed?

Probably in a very long time. Most of them aren't even huge issues. It's a lot of "if mordekaiser ghosts this one specific champion and this one specific thing happens then this tiny bug will cancel an AA or something".

I'm pretty convinced the bugs are with inherent issues deep in his kit. They won't be easy to fix at all. Considering that he is slated for a full scale VGU eventually and he isn't super popular, his bugs aren't exactly at the top of the list rn.

Probably when he gets a VGU, but they will have to just delete everything and start from scratch.