Stacking mechanic? I.e. Vindicta, Drifter, etc.
I'm not sure how they could do something that's different from Drifter, and kills during ult makes almost 0 sense since at least 90% of your KP in a game is from ult, but if they're going to keep her as a snowball character rather than having any scaling whatsoever then ??? maybe an option.
Only "reasonable" idea I have would be having something related to enemy boons scaling similarly to how Mo and K's bonus HP from ult scaling works on their boons?