Chaos Knight is one of those heroes who with the right amount of farm can absolutely wreck entire teams, but getting to that stage is usually the biggest problem. His skill set revolves mainly around increasing his STR to tank up his illusions, who are as strong as the hero himself, and can bash enemies to death.

Although most guides will have the same ability build, the item choices are where you can be different. Skadi is one of the best items you can build on him, which gives him a lot of STR and boosts his mana pool to beyond sufficient. Avoiding BKB or delaying it can be your best choice, and avoiding mid game items like Drums etc. are also recommended.