Bai Xiaochun had long since made his decision. He wanted revenge, but he needed to have evidence to justify his actions. Even if that evidence wasn't completely conclusive, he would at least need to provide some sort of explanation to the Grand Heavenmaster.
As far as he was concerned, this was the only way to get that evidence. Furthermore, there was no way that other people would have been able to guess that he would come to the Grand Asylum to perform interrogations. Few people in the world had ever served as prison guards, and fewer as inquisitors. Therefore, almost no one... would ever realize that the Grand Asylum was a place where countless shocking secrets were held!
To Bai Xiaochun, the Grand Asylum was the greatest weakness in his enemies' armor. After all, back in Giant Ghost City, it had been in Devil Penitentiary that he had learned about the rebellion being planned by the three great clans.