
Undertaker knight by me
In my world building, necromancy is a very dangerous practice, as it is basically breaching a hole between two plane of existence, trying to fish for a soul in the abyss of afterlife , which is a void full of unnamed eldritch entities with no form.
The natural of the dark abyss is that it amplifies and twists any input of any kind, emotion, intention, basic instinct. The action of said breech would cause some information of the living world to leak into the abyss, as if shining light into a dark sea, it attracts unwanted attention from things that runs on animistic instinct.
when infect with information leaked from the world of living that was twisted and amplified by the abyss , they began to take from and shape, and would crawl their way up to the breech, and if they enter reality, a devastation would sure come after.
Usually , in ideal circumstances the ritual could be stopped and the breech sealed. But if shit hits the fan and the creature had already honed onto the source and about to breech into the living world. an undertaker knight will be sent in to deal with such issue.
A knight paladin volunteer him/herself to be possessed by a saint with a ritual and becomes a vassal of their powers, but such powers are like overcharging a battery it will burn down the human soul and body. The undertaker knight will banish the creature and seal the hole , hopefully before they turn into ash.