Castle of Black Iron

Soon after the powerhouses of Huaiyuan Palace left that core area, the powerful qi had spread from the location of the Zhen Shrine to all directions, causing an earthquake. As a result, the houses and all buildings behind them started to collapse consecutively. All those with a slower response had been injured.

The fight between two knights was really destructive. When they rushed out of the inner city of Heavens Cold City, the complete core area of inner city had been totally ruined, closely followed by constantly booming sounds.

...

Zhang Tie, who was in Bluestone Pass Fort had also noticed the abnormal situation in Heavens Cold City. Even though it was dozens of miles away, Zhang Tie could still see the two battle qis rising into the sky like two columns of light reaching towards the sky...