Riot, adjust Zed's range for mimicked abilities
His mimicked abilities already have reduced damage/reduced slows, so why not take it a step further. Make it so that a shuriken from a shadow can only travel 600 units. Zed's poke goes from 1450 to 1150. And if a shadow only slashes area 195 units around it, that will weaken his waveclear/make it so that he slows fewer enemies. I used 2/3 of the standard range on his abilities as the reference number. The point is that Zed's kit is based almost entirely around his shadows, so why not just adjust the magnitude of the synergy instead of messing with base stats/base power?
Doing this will weaken his poke/harass, his waveclear, and his ability to finish off an enemy at range.
I feel like this is a better approach to nerfing characters. If characters are too UP or OP, adjust the magnitude (if a champion has no distinct identity, perhaps it'd be better to give it more kit synergy) of the synergy in their kits. For example, you could have Yasuo's Intent and his bonus armor penetration after ulting be affected by his Flow amount.