The first masked Demon, Yekun

Demons can be classified into different categories depending on the characteristics and qualities that they present. It is possible that even some of these categories of demons are not considered by many as such, since it is very common for demons of the spiritual type to be considered as ghosts or apparitions and not classified as demons. However there is a category, which cannot be described as anything other than demon, and they are the Fallen Angel type. They are not very typical and common demons to see, in fact there are seven of them alone, but they are quite dangerous and very difficult to kill. The demons of the fallen Angel type have a very particular characteristic and that is that they do not have a heart, or at least not in this reality. For each demon has its own region called Domain which is the place it comes from, and the place to which only that particular demon knows how to access. His heart is deep within the domain, so when a Fallen Angel-type demon comes to the human world, it is impossible to kill him, unless he enters his domain and his heart is destroyed. Yekun is one of the seven fallen Angels, and one of the first followers of the Devil Lucifer. Do not confuse devils with demons because they are different races that do not like to be confused. He was responsible for the creation of the rest of the demons, when he corrupted other angels and they decided to follow him. In truth, the domain are prisons that keep the demons locked up for a time, because when a demon leaves their domain it is weakened, and has to return from time to time to its domain before perishing. The gate to his domain is at Yekun Temple. When he was weak and needed to return to his domain, he received a visit from the Devil known as The Man with Multiple Faces or the Mask Collector, where he offered him the possibility of obtaining a body with a soul from which he could feed without the need of having to return to his domain to recharge. The Demon agreed, and the Mask Collector locked his essence with a sweet melody from his flute in a mask. That person who wears the mask will suffer a terrible fate, because his soul will serve as food for the Demon Yekun, and he will never have to return to his domain, as long as this process is repeated every 100 years.