Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This build with Cho is a very good tank build for him. The key to using Cho is to spam his rupture until enemies are at low health then move in for the kill.
In team fights it is crucial to hit as many people with his rupture and Feral Scream as possible because it throws confusion over the other team and they are unable to attack for a few seconds which is enough to kill a couple of them. Also, attempt to use your feast on the squishiest person in the group because it will completely remove them from the battle because once they see their health drop so quickly they will run.
Regarding the boots, ninja tabi or the mercury treads are useful depending on the enemy team.
KEY: Once you obtain your rod of ages you should know whether or not you will be needed as a tank or if you can build more ap. Don't be afraid to start building ap if you realize that they are not going to target you.
Also, the force of nature is key on cho due to the health regen and know your enemy teams attacks because you may be able to skip some armor or mag res depending on where the enemies damage comes from.