Art Style in Recent Splash Art
For those champions originated from a different country or culture, consider using different makeup styles. E.g. for Akali (clearly Asian-originated), use Asian makeup style. I do not mean manga / anime, but actual human makeup. It is quite disappointing that despite the game's international fame and large player base outside of the US, Riot still makes everything American.
American aesthetics is NOT THE ONLY ONE OUT THERE.
Many of the older champions have better diversity - they change things up for skins. As for the latest champions and / or updates, I'm just getting tired of the same thick curly eyebrows all of them have.