It's a lot like Random Battles with 1 stipulation.
Everything is Randomized, such as the Pokemon, Stats, Items etc. Usually Random Battle gives you viable sets with their Pokemon, but CC is absolutely randomized. For example: Modest Machamps, Golems with Sturdy holding a Focus sash, horrible Stats, and absolutely terrible movepools such as running 4 Normal Type Moves on a non-STAB Pokemon.