Rylais should be a 20% slow across the board
That's it. I dont care about the stats. It can have 100 ap and a shitton of health, but a 40% slow on an aoe effect is not okay.
Remember when you said you wouldnt buff bilgewater cutlass because "A slow on-demand from an item is too powerful"? Well a 40% permanent slow added to your kit from an item is too powerful.
I shouldnt lose half my movement speed from a rumble Q. I shouldn't lose 80% of it when trapped in his ult.