Mark

All living beings with souls, have a mark. A mark is a symbol that consists of an outer ring, an inner ring, and a centre ring that has a certain number of notches coming off of it. The number of notches on a centre ring dictates what Tier a daemon is. This mark acts as a sort of plug, preventing the soul from leaving the body through natural means, but breaking it severely can cause the soul to flood out of the body with extreme consequences. A Mark works in the same way to a summoning circle in a lot of demonic stories. The ring of salt/blood/runes keeps the demon inside of the circle, keeping it bound to the location.

Breaking this ring will cause the soul to forcefully escape, due to the amount of magic and essence built up inside. When this happens, the being splits into two forms; a soul, which dissipates quickly into essence, becoming a part of the world again, and what is left behind: a husk.

This husk is a soulless body, however is not dead. They are mindless, primitive beings that have one single instinct: to hunt down new souls to fill the void in their chest. This means attacking and destroying any and all nearby living beings, until it finds a soul that can fill it, but even then a husk cannot actually fill itself. They are doomed to an eternity of hunting, until their body gives out on them.

Breaking a Mark is the number one way to kill a daemon or a Numen. If a Numen’s mark is broken, they cannot create a new mortal form, as Numen and daemons keep the same mark between human life cycles.