Perception

It was necessary to obtain something personal from the target in order to cast a curse on them. It could be a drop of blood, a strand of hair, or a person's clothing.

Without any of these items, if one wanted to cast a curse on the enemy, one had to use one's spiritual power or gaze to lock on to the enemy.

If one could not lock on to the enemy, the power of the curse would naturally be greatly reduced.

Just like Yan Wushen, he had used the light of Buddha and easily purified the curse that had invaded his body.

Wujiang's spiritual power was unparalleled in the entire Battlefield of Celestial-Hunting. No cultivator could compare to him. Zhang Ruochen had moved more than 20 times, but he still couldn't escape from Wujiang's spiritual power lock.

At the end, when Wujiang cast the Chant of Death, he also cast the Curse of Light and Dark, completely trapping Zhang Ruochen.