Malzahar
As an Malz main he has become weaker since rework. Before rework he didn't combo for ak ill it was e-r dead now he needs w-e-r dead making him take more time for a kill, that's less time his ult will be up all game. Another factor he is weak is that he is played a good amount now and a lot of people know his kit and how to play around it, before no one knew how to actually play against him.
I actually quit playing malz because he the rework took a lot of damage from him, added more time a kill and made people aware of how tp kill him easily since they build qss now