Some summoners from Otaria have learned how to invoke their enemies’ nightmares in order to fight them. These creatures embody their owners’ worst fears and as such leave them paralyzed in horror. In the universe of Magic: the Gathering, «nightmare» creatures were a mechanic first seen in the Torment expansion. In it, whenever a Nightmare creature comes into play, another card or resource in play or in hand is removed, only coming back when the Nightmare creature leaves play. This symbolizes the fear the creatures provokes, freezing your opponent and leaving him without knowing how to properly react.

Background

Dementia invokers are trained by the Cabal to reach into the deepest depths of their psyche and unleash horrific monsters based on their own innermost fears and darkest imagination. These magicians travel the world looking for animals and monsters to observe and later pull out of their memories as twisted mockeries of their original forms. Sometimes they can even absorb the life essence of creatures they kill, locking it in the deep of their minds and using it as the basis for future grotesque summonings. Inevitably, spending so much time harnessing the dark side of their minds takes a terrible toll on the dementia invokers’ sanity. They all tend to become mad in the end; in fact, many become so insane that they are no longer able to function. Just a few keep enough of their wits about them to continue serving the Cabal and fighting in the pits. These dementia invokers are the most dangerous of all, because they combine intelligence, unpredictability, and psychosis in one terrible package.

Dementia Space

Dementia space is the term used for the space where a dementia caster or dementist keeps the monsters and horrors they can create. It contains the caster’s greatest fears and all the beings he or she has killed. Each person’s Dementia Space is different from everyone else’s, although they tend to have the same look or feel to it. In order to become a Dementia Caster or Dementist, one must have total control over the monsters of the first level of their Dementia Space. These monsters resemble all creatures a Dementist once killed. Dementia Casters are able to drain real creatures into their space. These creatures have minds of their former self and act so, but they’re nothing more than just memory.

Dementia Invokers twist their memories on creatures they have slayed in order to summon them as mockeries of the original versions. Dementia space is the term used for where a dementist keeps the monsters they create. Each person’s Dementia Space is different from everyone else’s, although they tend to have the same look or feel to it. In order to become a Dementia Invoker, one must have total control over the monsters of the first level of their Dementia Space. These monsters resemble all creatures a Dementist once killed. Dementia Casters are able to drain real creatures into their space. These creatures have minds of their former self and act so, but they’re nothing more than just memory.

In order to become a Dementia Master, a Dementist has to pass a shikar, a rite of passage used mainly to increase their imaination on creating nightmares by sucking various creatures into your mind. These rites are traditionally held in Krosa forest.

The nightmares

I created a template for summoning creatures under the 3e rules, and I tried toupdate it to 5e ones, but being summoning spells more restricted, I’m not sure how well they work yet. Lots of playtesting required. You can have a look at the creatures template and the prestige class who can summon them in this article: «Nightmares worth remembering».