The gravity realm was what the sect master of the Iron Fist Sect had insight in. Within the gravity realm, the force felt by one would increase five or ten times, immobilizing their bodies.
Out of all realms, the gravity realm was a rather special one. It was related to the magnetic field and gravity of the Earth.
When Qingfeng Li was trapped in the gravity realm and was immobilized, he understood this strong force. Of course, he had always wanted to practice the gravity realm, but he had no time until now.
Qingfeng Li started observing the gravity realm. He was originally a master of the grandmaster realm and had insight in the inferno realm, so he understood the gravity realm very quickly.
The focus of the gravity realm was on the gravity. As long as he understood the gravity he could control the gravity realm.