Honestly I feel like instead of nerfing champions like Ziggs or Kayle Riot should adress the thing that actually makes them (and similar poke champs) strong: Cooldown reduction.
Being able to cap your CDR with just 2 items (not even taking runes/masteries into account) is just ridiculous. Does Nashor's Tooth really need 20% CDR to do its purpose? It doesn't.
The thing that makes many ap mids so strong is the fact that they can get 40% CDR very early into the game which increases their dps substantially without sacrificing anything.
Same goes for support items btw.
Armor pen caster build + masteries/runes Varus is op as fuck in ARAM