With Evelynn, another champ that could previously be played both AD and AP is now limited to one type of damage. All her abilities now scale with AP and do magic damage. Previously, a few champs already got this treatment in their reworks/changes:
* Master Yi
* Nidalee (can still be played AD but it's pretty bad)
* Kennen (same as Nid)
I don't really know why they are doing this, but I really don't like this trend. Being versatile is not a bad trait in my eyes and supports the building of a bigger pool of viable champions. Being able to adapt to one type of damage before or even during a game is something very valueable and unique that I always really liked about this game.
Now, the only champions that you can actually still (**_more or less effectively_**) play either full AD or full AP are Ezreal, Kog'Maw, Shaco, Teemo and Twisted Fate. Also somewhat Trynda but his AP scalings got nerfed after he actually got played AP in LCS at some point, not sure about his current state.
Dunno if people share my opinion in this regard but I'd like to know nontheless why Riot decided to do this. I probably forgot some champs in my lists, feel free to add any.