Hidden Weapons are weapons that are designed and created by Tang Sect in order to assist in combat and to perform assassinations.
Hidden Weapons are often used in combination with poisons in order to maximize their effect. The strength, speed, explosive power varies from weapon to weapon.
The creation of Hidden Weapons is a strenuous and delicate process and one needs to train for several years to effectively create and assemble them.
After being reborn with the memories of his previous life Tang San create hidden weapons to assist him in combat.