Idea for Kayle's ultimate

The idea is the target which kayle ults will take 50% healing from the dmg taken when she ult herself she will heal for 75-100% of the dmgtaken this will great idea decided to give kayle i great boost in the late game which will be great for kayle and something smaller idea for the healing can scale with 10% of her ap 1000 ap= 100% healing from the champion this will better for her. I think that the scalling can be lower or 10-5% ap scalling 1 upg-5% scale 2nd upg 7,5% scale and at 3rd lv ultimate she will have 10% ap scalling.Send something to after you see this is the idea good or bad pls