I've been playing a lot of 
recently, and I've also been trying to get mastery 7 on him. Since I still have 2 mastery 7 tokens left to earn on him, I'm starting to look for new builds to try out that are better than my builds for him right now. My builds are listed below.
AP: 
Tank: 
If anyone has any improvements to my builds, or any new builds that I could use, please let me know.
Depends on what your Team needs and what you are against. For the Tank replace the boots with Ninja tabi's depending on the ADC. My main suggestion is to not seperate the AP and Tank by too much. Try a Singedy type build. In which you combine 2 AP items and rest tank.
If you are full AP you want 
. I dont think rylais is worth with its low stats, if you can slow with W you can hextech in anyway. You list your build as though you build it evergame but you should build void staff sometimes.
I never build AP Cho as tanky as you do, but maybe its good.
If you think you have a shot at killing your laner you can go 
and start building AP and just forget about rod. 
doesnt help you burst someone down, all though it does let you use mana on minions more or stay in lane a long time. You can build 
vs someone rushing 
.
'
The tank build is easy to kite, you need atleast 
because if the nemy are grouped and they see you on the map, they can just chase you down if your team isnt around. You dont need to be close to be out of position with Chos base ms and the mobile champs. Also increases your chances of escaping a lost teamfight, which otherwise is a 0.0000001% chance.
/ 
definatley and you can choose between these items 
