Lich are strong, X-Class Yokai that resemble skeletal beings, that are considered undead by definition.
In a similar fashion to Mummies, Lich have to be created artificially. All Lich were humans, before they made a deal, and sold their soul to demonic forces, in a desire for greater power.
The majority of Lich are basically skeletons, or at least withered, and visibly aged. This is because, even though they are granted immortality, they are not granted eternal youth, and continue to age and decay until they are nothing more than bones. Some will use their powers to take their human form, which resembles how they looked before they gained their abilities.
As a result of the deal they made, the life force of a Lich is tied to a given object, normally some kind of a reliquary, or even possibly a live organism. Their entire being is bound to that item, and it is normally the source of their power.
The majority of Lich generally are pure evil, and use their powers to reap destruction, and chaos upon the world. Not all Lich are so evil, and many instead prefer seclusion from the rest of the world, normally living as recluses in mountains of forests.
AbilitiesEditLich are immensely powerful, and are unrivaled when it comes to forms of sorcery. Due to the demonic powers that their deals have granted them, Lich are capable of conjuring immensely powerful spells, similar to that of Witches, but to a much higher extent, possessing enough strength to overpower a Witch in a battle of magic. Strong Lich are even capable of summoning some of the demons they made a deal with to serve them.
Their given reliquary is the source of their power, and is the way they channel their abilities into form. However, their entire being is tied to their given item. As such, if their precious item is destroyed, then their entire being is destroyed as well. The demons they sold their soul to, will instantly come to claim the life of the Lich as their own, and they will turn into dust.
Due to their status as being more dead than alive, Lich are generally invulnerable to most forms of attack. They are even capable of losing their limbs, or their heads.