Black Cleaver should not be built on Assassins or Marksmans
Black Cleaver is a Juggernaut item that is suppose to help a Champion utilize their high base damages through the 30% Shred and 20% Cooldown Reduction, as well as encourage long fights by having the Shred stack up over time and having HP as one of its stats. However, I feel like right now Assassins and Marksmans are making inappropriately good use of it.
Now that Assassin items and flat Armor Pen has been reworked, Marksmans should be using Last Whisperer upgrades instead as their % Armor Pen item, instead of exploiting Cleaver's CDR and Movement Speed.
Assassin's should not have access to %Pen items, as they're suppose to be weak to fighting targets with lots of Armor, and instead should be using they're superior mobility and tricks to outsmart these types of enemies, rather than just brute forcing them.
I believe this problem can be solved by simply changing around a few stats of the item. Such as... AD: 50 ---> 30 (-20 AD) HP: 300 ---> 500 (+200 HP) Build Path: Phage + Caulfield's Hammer ---> Phage + Kindlegem or Phage + Jaurim's Fist
This will help push it back into where Juggernauts want this item to because they can make good use of HP and don't mind losing that AD since their bases are already great, while Assassins and Marksmans will have to make a trade-off if they want the CDR, %Shred, and Movement Speed, at the cost of a pretty big damage loses.