The Restriction Technique originated in ancient times and had a wide range of uses. It had once been indispensable for setting up formations, controlling enemies, sealing off information...
However, the threshold for learning the Restriction Technique was very high. Combined with its complete lack of flashy effects when used and its inability to attack directly, it had gradually come under threat of being lost.
Restrictions were divided into long-term and short-term types. Long-term restrictions generally lasted for years or even a lifetime, while short-term restrictions generally lasted for days or months.
When used on a person, the Restriction Technique could leave a restriction inside their body. Once that person tried to reveal certain information or entertained thoughts they should not have, the restriction would trigger.
Once a restriction was triggered, the afflicted person would suffer pain worse than death in milder cases, or breathe their last in severe cases.
The Tang Sect to which Tang Mo belonged had originally been a family-based organization, formed by members of the Tang family who shared a common ancestor.
But as the times changed, gaps between generations could easily arise: the older generation of powerhouses would be hanging by a thread, while the new generation of geniuses had yet to mature, or there might not even be a new generation of geniuses at all.
The Tang Sect had therefore been forced to accept people with other surnames and establish an inner sect and an outer sect.
The inner sect still consisted of Tang family members and held the dominant position within the Tang Sect, while those with other surnames joined the outer sect and accepted the inner sect's leadership.
To prevent outsiders from leaking the Tang Sect's secrets or betraying it, the inner sect had developed a set of restriction techniques at the time.