Black cleaver's CD reduction isn't unique passive?

Sure, I can hit this.

Armor Penetration Pre-Season 1 looked liked this:

1. You could start with 40+ armor penetration. (Recall, we nerfed flat armor penetration runes)
2. Last Whisper was overpowered. (+40% AS, +20 AD)
3. Green Elixir was overpowered (Gave roughly 50% more statistics.)

The problem with armor penetration in this setup was that flat armor penetration was the de-facto standard for your rune page as a carry, but Last Whisper was also the highest damage multiplier after your infinity edge, and Green Elixir could fill in for the critical strike.

This led to carry damage turning on at roughly 17 minutes with full armor penetration.

In today's world - look at the differences:

1. Green Elixir is weaker.
2. Flat armor penetration runes are weaker than before.
3. Last Whisper isn't triple multiplicative statistics, only double.

It's much harder to full-spec armor penetration *and* have all your other multiplicative statistics at once. Basically, we changed the armor penetration formula to hurt carries - but the actual problem with carries was the ease of their build up.

Question: If Jarvan buys the new Black Cleaver and auto-attacks an enemy to proc his passive, does this apply two stacks of the BC armor shred or just one?

I was just wondering if something would be done for the haunting guise as was done for chalice. That would be really helpful as right now haunting guise in late game is pretty horrible.

% penetration actually becomes good now?! OMG.

Can you guys give the amount of item that are being added, the ones that are being reworked and the ones getting removed? Just numbers would do it fine.

There is this really big discussion but it was mostly only about a single item.
There isn't going to be more items that are being made for AD Caster? It feels like the BC change is the only item going for AD Casters.

Alright.. I've seen enough about penetration, and BC.. and it looks lovely and all.. but I play support, Xypherous.. Please give me a teaser about these new support items that were mentioned.

Ok, just as a question, how does this effect Urgot?
I mean, does his E dot and his Q apply the BC proc, even thought his q doesn't apply on hits?

Edit
What I meant is, will this allow Urgot to scale better into early game?

Xyph has basically already answered this. The proc applies on ALL physical damage, including dots. So, yes, Urgot's E and Q would both apply the armor shred effect.

All sources of physical damage proc the effect. Using the example Xyph mentioned awhile ago, Garen's spin to win procs the effect 6 times, since it hits 6 times.