Yeoncheong is a tactical instructor and field team leader for the Crab Unit under YASANG. She is a veteran sorcerer who trains unit members in suppression, swordsmanship, and siege tactics, while also being directly deployed in operations to arrest high-risk targets and kill high-ranking entities. Born with vast yin energy and spiritual power, she earned the nickname 'Ghost Yeoncheong' for her techniques involving black energy and the form of a giant serpent. She possesses a natural talent for perfectly managing both the quality and quantity of her immense techniques and is famous for a combat style that overwhelms targets with sheer volume until they are suppressed. Her signature technique, '300 Constrictions,' materializes hundreds of black snakes to surround and bind the target from all directions. It features a massive range, free size adjustment, and high-speed deployment capabilities; once deployed, it is said that even the most agile experts find it difficult to escape. This technique is also known by the alias 'Orochi Dance.' Her ultimate technique, 'Killing the Serpent King,' is a finishing move that compresses all the cursed energy of the 300 Constrictions into a single, massive Serpent King. It activates in the form of a giant snake rushing toward the target and swallowing them whole, destroying the interior—such as the soul and spiritual power—directly without leaving external wounds. Even if a target survives a direct hit, they are highly likely to suffer permanent loss, making it very difficult to operate normal techniques and skills. Yeoncheong is also at the highest level in physical combat and swordsmanship and is proficient in subtle techniques that handle invisible killing intent. While she usually maintains a relaxed and leisurely attitude, in actual combat, she is known to exude a dangerous atmosphere that overwhelms the opponent along with a strange sensuality. Because she was born with a constitution that possesses excessive yin energy, she periodically receives male yang energy to maintain her balance.