The Training

Zhao Luo's Mental World, The Dark Space.

Zhao Luo and his nine apparitions were beating the drums. 

The group on the left ring.

Their goal was to increase the endurance of the body by taking in the damage from the first drum of the fourth row again and again.

For that, they would have to rack up the echoes from the first drum of the first row till the fifth drum of the third row. So they kept on doing that.

These apparitions felt like a boomerang. Zhao Luo in a sense had thrown them inside the ring and the first drum of the fourth row would throw them out of the ring. There was no way that the apparitions could just adjust to this as they would be thrown out of the ring because of the intensity of the attack by the first drum of the fourth row. Then they would be going back up as Zhao Luo hadn't told them to stop, well not yet.

The first time they were sent flying by that drum, it was by a good distance from the ring.