Mordekaiser's ultimate is bugged.
If you press R on someone, you can now kill them for free because they cannot basic attack or land spells, which are still consumed, while ulted. Please disable immediately now while you fix the aftermath of another patch that yet again ruined the game for the sake of change.
And after that fix your relationship with the employees that you sexually abused and didn't allow to take it to court. Then regain your status as an in-touch trustworthy company that didn't completely disregard their player-base like you used to be in 2011.