At the ancient battlefield, Su Xin was unaware of the presence of Ye Jianan, the "Two-Faced Vidyārāja" from Happy Temple, and even if he had known, it wouldn't have been useful to him now.
Originally, Su Xin had wanted to use the dense fog at this location to his advantage to set a trap for the people from Happy Temple, such as collaborating again with the people from Netherworld to ambush and kill them. However, he ended up discovering that it was unfeasible.
The deeper he walked, the thinner the mist became until even the suppressed spiritual senses of a martial artist were released, so if he teamed up with someone from the Netherworld here, it would be very easy to get discovered.
The biggest difference between the very center of the Ancient Battlefield and the outer world was the intensity of the battles.
