Clone Drone in the Danger Zone

In Chapter 2 Level 7, there is a secret area you can access after completing the level. After killing all the robots, there is a jump pad and a wall of columns to get back to the elevator. Use the jump pad and head to the platform on the right where you'll see a pink line. Follow the path and it will open up a small area, walk into it and the achievement will pop.

This can only be done on Chapter 2 Level 7 of Story Mode. After completing the level, before jumping back to the elevator, use the jump pads to reach the ledge right of the elevator. A fake wall will move revealing the war cubes. They will enter the arena and then fly off unlocking this achievement!