Alei.
A high monk from the Yuanlong City Kongo Temple and a high-order warrior who had accomplished "Opening the gate."
During an outing outside the city that centred around treasure-hunting, Alei and his teammates accidentally fell into a hidden Shaen Nest... To allow his teammates to escape, Alei alone held off the swarm of insects.
When reinforcements arrived, the insects were gone, the nest empty, and Alei was nowhere to be found.
Just when everyone had concluded that Alei had died,
in the depths of the nest, the leader of the Shaen insect swarm, a Parasitic Ancestor Body, attempted a "Perfect Parasitism" using the flesh of this monk.
Because Alei's willpower was extremely strong, even to the point that when this bug used its race's innate secret art of parasitism, it could not erase his will... leading to a fusion of consciousnesses and giving birth to a new individual with a bizarre personality.
Sometimes brutal, sometimes gentle.