Now that I got your attention, at least read before downvoting due to the title.
People complain that the Black Cleaver is OP, or combined with the LW, armor stat in general is completely useless. But on it's own, other than being a really good item is it actually horrendously OP?
Maybe % and flat on one item may be a bit much in certain cases, but it isn't a extremely OP item on it's own compared to when combined.
In season 3, Riot wanted to sorta steer away from the "one build rules all" method for most characters, and tried to introduce new items to help liven up the builds, especially support with the new awesome items. But all the different areas were just too great... instead of choosing we could simply take the best of each category, and make an insane build from that.
I'm talking now about FLAT armor pen, and PERCENT armor pen.
Both are great for a champion that can use it well
FLAT armor pen champions can take down squishy enemy champs fairly quickly
PERCENT armor pen champions can still compete against tanks without being quickly dominated in return.
So a simple suggestion:
Remove the % armor pen from Black Cleaver. Increase FLAT armor pen, and make the new passive increase FLAT armor pen in some way or form. (i'm no math genious, someone else can do the numbers :P )
Slightly lower the PERCENT armor pen from LW. Perhaps by like 5%? Now add a tweaked, but similar version of the current BC passive onto LW.
The catch? Once you build one of these items, you cannot build the other. Also, they do not interact with other champions, to avoid one or two people building BC, the other few with LW to recreate the same effects. The deductions only apply to the one that dealt it.
Now you've got a choice, a strong FLAT armor pen item, or a strong PERCENT armor pen item. Locking out choices seems counter productive when the goal is a "huge diversity" of item builds, but it makes you decide. Do you want this, or do you want that decide because you can only choose one for that game.
Now, i would make a "lengthy" list of possible items that lock another or something of that affect... but my idea mostly came from the armor pen problems, and adressed to the armor pen problems. Who knows, it's still pre-season. Suggest something, it might work out really well
And just to throw something out there... 2 random suggestions.
If a Ruby Sightstone is part of your inventory, allows your boots to become an active item with an unique passive. Allows the placement of *1* Pink ward at any place lasting 30 seconds. Holds two charges, but you must wait until your previous one dies out and an additional 15 seconds. refills once you go back to base. First pink ward can replace the old pink ward if you somehow get there in less than 45 seconds again.
If a Shard of True Ice, Twin Shadows, Shurelya's Reverie, or a Eleisa's Miracle Is in your inventory, allows you to buy the Golden Enchantment. provides a permanent 2-4 gp10 to your boots. If Eleisa's Miracle turned into your passive stats, still counts.