Chaos Knight is a hero that needs time to farm up his items so he can be useful in fights mid / late game. I recommend playing Chaos Knight in Radiant bottom lane or Dire top lane only. In lane, be sure you have a ranged support to harass the enemy with so you can somewhat peacefully farm. During early game fights, you should be farming if you can. His skill build focuses on maxing Chaos Bolt and Reality Rift before getting his ultimate for max survivability early on. As always, let me know what you think!