The Square Sword Formation was a high-level skill and sword technique. It was already one of the best among the Adventurer professions.
After all, it was a skill book kept at the National Special Department's headquarters, so it was naturally not low-grade.
Chen Kun did not hesitate and immediately started learning skills!
"You are learning the skill, Square Sword Formation…"
"Learning failed… This skill is not a Chaos Martial Monk Class Skill…"
"The Boss' authority has taken effect. You have successfully learned the Skill, 'Square Sword Formation'!"
"Authority increased: The Square Sword Formation is a rubbing of the ancient Immortal Slaying Sword Formation. Authority repaired and upgraded. You have successfully learned the Immortal Slaying Sword Formation!"
"You have obtained the Boss Skills, Immortal Slaying Sword Formation!"