**My current thoughts on Black Cleaver:**
_Note I have limited games due to the long wait times to be able to test the item since I refuse to play in anything other then 5v5 with actual humans for results. _
Black Cleaver is is very good in 2nd, 3rd, or 4th slot due to how item slot efficient the stats are for most top/junglers. It is a very bad rush item in most cases due to how ineffective the % armor pen is in the early game so most bruisers would prefer to go Ravenous Hydra, Cinderhulk, Trinity Force, or Brutalizer then build Black Cleaver. 40% CDR is achieved with this item + 9 CDR glyphs + 2 points into sorcery + another 10% CDR item of your choice.
CDR 20% -> (10%) or (15%)
Most AD champions that utilize this item abuse CDR very hard such as Udyr, Hecarim, Wukong, Trundle, and Rengar. It also reminds me of old spirit visage on how it used to give 20% CDR. Then was nerfed to 10% because people build it due to how strong CDR and how many items it normally takes to cap out CDR
Phage Passive on hit 20 MS -> 30 MS
I feel like this item wants to be a sticking tool but does not really have the stats to give it that besides the CDR which makes it slot efficient on most champions. With this you would be slightly faster (by 5 MS) then champions who have tier 1 boots and also share the same base movement speed as your champion when you do not have any form of boots.
(6 stacks [5% reduction each stack] -> 4 stacks [7.5% reduction each stack]) (Duration 6 seconds - > 3 seconds)
I feel like the item does not work fast enough for what it is supposed to do. This change provides counter-play to the item by making you commit to keeping the stacks on targets.