Riven Shield

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I personally don't know if this is a good reason to have it scale off of AD. For instance, Yi's kit wasn't meant to be a Health or AP stacker, but his W heal scales off of AP. There are plenty of abilities (defensive or otherwise) that scale off of an attribute that they do not stack. That being said I'm glad that I'm in an ELO where Riven is not all that common (silver) :) She scary.

But your mistaking it here Yi was one of the first few champs to be designed if i recall correctly, back in the day Riot decided to add random AP ratios on champions

1. so baron buff was still effective on them
2. FUN STUPID BUILDS

Riven's case is untrue, the comboed fact that she is quite literally designed to be a fighter-assassin type champion that builds AD, they'd have to miraculously compensate her E shield

{quoted}

I personally don't know if this is a good reason to have it scale off of AD. For instance, Yi's kit wasn't meant to be a Health or AP stacker, but his W heal scales off of AP. There are plenty of abilities (defensive or otherwise) that scale off of an attribute that they do not stack. That being said I'm glad that I'm in an ELO where Riven is not all that common (silver) :) She scary.

Yi's W heals based on a value of % missing health as well however, on top of the ap ratio. Riven's shield is flat bonus AD scaling only.