Talk:Black Cleaver/@comment-134.130.4.243-20100925153434

combining with Last Whisper isn't optimal, because Armor Reduction is always applied before Armor Penetration.

this means: with every hit of your Black Cleaver, your Last Whisper will get less efficient. If you grab BC, then go for a different attack speed item. If you need more Armor Penetration, then use flat one or Armor Reduction

Synergizes well with Stark's Fervor, because Armor Reduction can reduce armor below 0, resulting in additional damage.

Question: the passive isn't unique. Does anyone know what happens, when you stack 2 BC? Do you get -120 armor, or do you just stack the debuff faster?