Gu Hang couldn't help but accelerate the expansion of military forces due to an imminent matter, not to mention his personal anxiety over the weakness of his own direct lineage and his paranoia about being persecuted.
Previously, there had been an attack by 'pustule monsters' within the Governor's Camp. Subsequently, Yan Fangxu led an investigation into the source of the monster attacks and discovered they were coming from a forest to the west.
Afterward, while Yan Fangxu took his soldiers for training, they used it as both a training exercise and an opportunity to exterminate these monsters.
They had no idea until they went there and were shocked by what they found. They encountered many monsters in that forest, not just pustule monsters. And they even discovered numerous monster breeding nests.
Gu Hang himself went to check it out.