Dunk Scrubs and get snatch with my highly renowned challenger GATH build

Build ap, get kills, no glacial required because your **** hot.
carry games with you superior skill and rank up out of bronze.

Playstyle

Cho is not always a good idea to pick but he has some of the best cc and burst in mid. He can be destroyed by marksmen and long range control mages, but he has very favourable matchups with low-medium range squishies. You never really want to blind cho but he is a good flex pick (top and supp) so he is not always correctly counterpicked.

If you plan to roam you want a sweeper and/or a pink ward. this allows you to avoid wasting time and is essential for worthwile roams.
while cho isnt the best at roaming, by using hexflash you can make some good plays as they will 100% not expect it.

Runes

You will see many scrublords here claiming that comet or aery, even glacial (yikes!) is good on chad'gath. the truth is that these people are meta scrubs and lack the ability to make their wives come let alone dunk scrubs in league. However I have tirelessly worked with the population of the trap house and have come to the conclusion that Crack Harvest is the only choice in runes. It gives you a massive ammount of burst (Q+W) and you can 1 - 2 shot ANY squishy after double pen and some ap. this allows you to carry almost any game permitting your team is devoid of scrubnoob or hashinshin.

cheap shot does good damage but can be swapped with taste of blood

eyeball can be swapped for anything personal pref

ravenous hunter the healing is pretty overtuned but this rune is choice. I would avoid ult hunter and ingenious

hexflash can be useful situationally especially when you can jumpscare them from over raptor wall or from brush, also useful when ganking botlane/toplane. I would take this if you plan on roaming but if you arent then go for approach velocity.

biscuits/approach velocity If you are spamming Q in lane you can run out of mana pretty quickly, the last thing you want is to be unable to rotate to an early fight due to being oom. This rune is personal preference But I beleive it gives you a good bit of safety in lane knowing you will always have some backup mana. approach velocity synergises great with your Q and E so its always a solid alternative to take.

Itemisation

Since the pre season is here we have new items, some are good but must are net neutral for cho. The removal of obliv orb has hurt him as he has doesnt have that cheap flat pen. however ludens gives 10 flat and 5 per legendary. This means he will have the same/or more flat pen than ever before.
building rocketbelt to get sudden impact proc is just not as good right now but it is far from bad. You really want to be going ludens most games and follow it up with a horizon focus or zhonyas. because zhonyas is now 2500 (from 2900) however it gives 10 less ap (which is nothing).

Starting off with triple dorans is gone as they don't stack anymore. So I would advise to rush sorcs or lost chapter, then finish ludens. you can always buy a dark seal as its cheap and gold efficient. flat pen is very valuable on the gath as you have good base damage on your Q and W. After ludens you can buy a stopwatch to preserve your shutdown or go into a horizon focus or cosmic. after that you can really build what you want.
I would only suggest Rabadons after 2+ items as its only really gold efficient after that.

This guide may not be perfect But I urge you to experiment and try new things.
Thanks for reading! Good dunking, my fellow chads