Performed major rework of build.

Flat CD is awesome until level 13, when you're casting rupture... once a wave.

After that you have to start teamfighting, which is when you really want it, because then you won't be wasting your mana on creeps and can actually be in a fight where it's useful to fire more than one spell at a time.

The reason you take the wraiths is because they give WAY more experience than the other neutrals and leave you at the highest health level 1. You can't take both golems off the bat without healing or being at 2/5 hp to start off in lane and wolves don't give much exp at all.

Ardor, Strength of Spirit and Resistance are useless. 6 magic resist? Sorc boots penetrates that. HP regen based on your max mana? Wow, an extra .5 hp regenerated every 5 seconds. 2% attack speed increase? Whoa.

Max Defensive Mastery and Dodge/Nimbleness. They're the third and fourth reason you take defensive tree at all.

Also now your guide is missing a sixth item. You might want to take Warmog's earlier if it's your only source of HP, because it takes time for it to build to its potential (read the item, I think it's 15 minutes until it's maxed). What item do you open? I hope it's not book. Regen pendant first for staying power in lane, anything else and you're going to be harassed to death.

Hehe 5HITCOMBO starts to harras any other Cho on this site as i do with WW :)

@ guide

i am quite confused by your boots choice.

OH! One more thing to add. Go 9/21/0 instead of 9/0/21. Smite/ghost isn't worth putting 21 into the utility tree for, the buff duration isn't as important as the reduced damage from minions, especially when your base movespeed is so low at an early level. Also, veteran's scars gives you an extra 60 hp, with hp quints that's 160 hp more at level 1. The 5% damage reduction is nice, too. With his passive and mp5/level seals you won't need meditation.

Also, a nice trick is to go to the wraith spawn off the bat, rupture them as soon as they spawn, smite the big one, auto attack the small ones, kill one small one, hit the second one twice, rupture and hit the other one twice. You should kill them all, get ~100 gold, and after 2 minion kills in the lane, you're level 2.

Nashor's tooth and berserker's greaves are terrible on cho because you're not really going to be relying on auto-attack for damage with mejai's and lichbane and the cooldown isn't worth wasting an item slot that could be mob boots/merc's treads or frozen heart for cooldown. If you're going to go attackspeed, go DPS cho. If you're going to go mejai's, go caster. Don't try to do both because it's splitting his abilities too much, he doesn't add much to the team trying to fill 3 roles at once. Your survivability is pretty low with this build and it's going to be hard to stack out mejai's, especially as your first item. I think you should open regen pendant. It's important to take mid lane with a build like this, so you should probably mention that, and with max rupture/feast and a point in scream early you won't have nearly enough mana to hit them with your combo at an early level even if you last hit every creep in the wave. Take mp5/level seals instead of AP, an extra 20 ap at level 18 is worthless. All of your glyphs should be cooldown/level, after 6 (when you get feast) it's better than flat CD runes. Make your quints flat HP, the extra 100 hp at level 1 helps a LOT in lane for getting last hits. Void staff is probably not the best item on cho, I'd say zhonya's outclasses it, especially with lichbane.

Otherwise, looking good, keep practicing!