Black Cleaver getting reworked
So, I checked some PBE updates, skins getting put in that look cool and interesting, new (old) mechanic getting put into ARAM/loading screen update, then into item changes I saw what they're doing to black cleaver, making it an upgraded phage, removing the armor pen/shred and upping the health some.
My thought on that is, please don't. I do think that the phage should upgrade into something and keep a similar/upgraded effect, but to get rid of a key item for shredding armor just seems plain wrong unless there is a replacement item in the works. Because otherwise if you're playing a tankbuster type champ, building a Youmuu's is gonna look pretty silly, especially on champs like Vi, Renekton, Garen, etc. It can work, but the extra ms/as is pretty wasted especially on Renekton who's a spell-casting (kinda) bruiser.
Whoever's on the item changes, I want to agree with what you're doing but please keep Black Cleaver as it is, and add a new item in for the Phage upgrade.