The Black Cleaver
+50 Attack Damage
+10% Cooldown Reduction
UNIQUE Passive: +10 Armor Penetration
Passive: Dealing physical damage to an enemy champion reduces their Armor by 5% for 4 seconds (stacks up to 5 times, up to 25%).
(Armor Penetration: Physical damage is increased by ignoring an amount of the target's Armor equal to Armor Penetration.)