Very true. I play burst so Youmuu's Ghostblade is for me.. But also consider this.. As you say, Crushing Blow lowers to 70, if you had Youmuu's.. It would take them to 50 with the 20 ArP... So you got 8 more armor, BUT you add in only 10 less damage (40 to 30), CDR, Critical Strike chance, and the active which adds 20% movement speed, 50% attack speed for a maximum 8 seconds with full stacks, and a 60 second cooldown (with CDR approx. the same time as your ult gets back up)... Add in marks and or quints and armor is even lower still. I find the added bonuses from Youmuu's to outweight the 8 armor and 10 damage you give up from Last Whisper.
Just food for thought.

i think even if crushing blow gets added first its still better then flat apr.

lets say you have 100 armor

30% off with Crushing Blow --> 70 armor left
now get 40% from Last Whisper --> 42 armor left.

So you have an effektive apr of 58% With my recommended build you do enough dmg do hunt down squishy champs and you can get quite annoying for tanky champs like irelia. but yormus blade instead of last whisper might be also a good option. actually it just depends on your way of playing.

Flash is kind of unnecessary for wukong, seeing as he can decoy out of thing fairly easily. I'd pick ghost/teleport, decoy/ghost if things are getting dangerous.
and if the enemy team has alot of stuns and slows i'd get tenacity boots.

But if you prefer flash thats okay too. Its a bit unnecessary but can still be viable to some degree. Also i'd get armor quints and marks.

Thats all I had anyways, rest of the build looks viable.

I would say you need to include an alternative item section, or if your multiple build are your "alternative items" then a section explaining the difference in builds. The difference in builds in my opinion should be added either way to inform everyone of exactly what you're doing with each build. The Items section you have is too cluttered with text in my opinion to effectively and efficiently get your message across.

Also, for Wukong, the flat armor penetration is actually more beneficial, because the last whisper % ArP get's added in AFTER everything else.. The way to go is definitely flat because you get the % reduction from crushing blow FIRST, THEN the flat armor penetration from items and runes, and LASTLY the % ArP (aka last whisper). Which at this point you have already negated their armor to the point where the % will be dismal. Furthermore the % armor pen is better for people with high resistances (aka tanks) not the squishy DPS targets that Wukong should be targeting.

As a personal preference I like CDR on Wukong because I feel he is more Burst than anything, but that's just my opinion

For complete information on how ArP works, see this link: http://leagueoflegends.wikia.com/wiki/Armor_penetration

ok i changed it and also added some content at the different builds on top of the page.

ok i try to change it as soon as i find time for it. i hope someone is going to test the build soon^^

Easy way to improve the guide: If you put a skill, hero, item, rune, mastery, anything really, in double brackets it will make it show the item's stats when you hover over it.

For example: Wukong, Presence of the Master , etc