QUOTE(EARL_SWEATSHIRT @ Feb 24 2012, 02:01 PM)
Black cleaver is a really bad item. You don't need it unless all of them start stacking heavy armor. Last whisper is sufficient.
It's the other way round. You only need Last Whisper if all of them start stacking heavy armor. Otherwise Black Cleaver does the job better.
Let's look at the figures.
Black Cleaver removes 45 armor.
Last Whisper provides 40% armor penetration, essentially removing 40% of target's armor.
If your target has above 110 armor, then go Last Whisper.
If not, then Black Cleaver is better.
Why 110?
Because 40% of 110 is 44, still less than the 45 armor reduction from Black Cleaver. So 110 and below, Black Cleaver is more effective by removing more armor. Above 110, then Last Whisper is better.
QUOTE(EARL_SWEATSHIRT @ Feb 24 2012, 02:01 PM)
Wits end is a great item on the other hand. I get it on a lot of champions like Irelia/Nocturne/ Those who benefit heavily from physical attacks.
Wits End provides additional 42 magic damage, which in no way benefits physical attackers. Physical attackers rely heavily on abilities like critical strikes and life steal, both of which remain unaffected by the magic damage generated. IMO, Wits End is best used by on-hit builds which deal the majority of their damage in the magic portion of an auto attack, in conjunction with items like Madreds Bloodrazor.