Ok, let's break this down a little bit, since I looked up this game.
Cho'Gath had 20 kills at this point in the game. He had:
- Cinderhulk
- Spirit Visage (great purchase, considering he had 3 oceans (15% of missing health healed every 5s) and a potential Ocean Soul coming up
- Thornmail
- Righteous Glory
- Gargoyle Stoneplate
- Warmorgs (he didn't have boots at game end) - Elixir of Iron.
This is the perfect build for what Cho's going for this game. He had 24 stacks of ult, too.
Now, in the video we see Xerath plinking away at him, doing essentially nothing. There's no grievous wounds applied, because for some unknown reason, Xerath didn't purchase Morellonomicon for Grievous wounds.
Against this team, which is fairly tanky and features Darius and Renekton, Grievous wounds is essential.
Only 2 champs on Cait's team took Grievous, and you can see it's effect on Cho and Co in the 2nd part of the clip. Cait DOES do some serious damage to him. When Aatrox gets involved (he also had executioner's, but since he built Lord Dominik's Regards first, I have to assume it was just far too late in the game to make a difference), it gives Cait a little more front-line to start really tearing Cho'gath down.
Jax had no excuse here, he needed an executioner's calling too tbh. He weirdly never finished his jungle item, either.
I really enjoyed watching this video btw, this Cho'Gath knew what they were doing with that build! Ocean is the only dragon buff and soul that has any form of counterplay; and it's only 800g for AD based champions.