In a cavern, hidden in some part of the Central Region of the Blessed Continent, an abnormal 'monster' was born.

Proving its special traits, as soon it gained awareness the monster completely ignored the effects of the demon energy in the form of miasma gathered in the cavern and calmy judged its situation. To the current age where any magical beast that enters in contact with such evil energy is forced to either completely resist it and strengthen itself, adapts to it and become a demon beast, or lose its reason and intellect, becoming a monster following its instincts.

Inside the monster’s body, stood not a simple soul, but a reincarnated one. One that inherited the memories, experiences, and values of its past life, but choose to stand as a different being, with a different ego.

The Original Demon of Lust – Vhod Luxuria was dead, the monster concluded in its mind, already identifying itself as ‘herself’ under the influence of her memories. But with respect to her past-self, the monster decided to use her previous identity to produce a new name.

The ‘Rayel’ name from her past-self time as a human of the now distant and foreign world of Earth, and ‘Vhuria’ surname from her past-self name. Far from creative, the monster Rayel thought, but she felt satisfied and that was what mattered to her. (A/N: VHod + luxURIA)

Following the creation of her new self, Rayel reviewed the power and plans left behind by Vhod before the demon-turned-spirit decided to die. After making sure that everything was working aside from the seals on her memory to avoid a meaningless burden upon her soul, Rayel returned her focus to herself, or better, to her current true body.

Slime Chimera, a mutated slime capable of devouring the traits of other beings and adapting to most changes, while also being capable of changing its body according to what it eats and wish.

Coldly analyzing her current body, Rayel felt confusion and wariness. Why such a creature was born in the miasma-lacking Blessed Continent and not in the Demon Continent, where even vegetation has to adapt to the excess of the corrupting energy?

Using Vhod’s memories, Rayel quickly found a possible answer: divine intervention. And this answer bought serious worries to the still ‘weak’ Rayel, for in Vhod memories she found which ones of the gods had the authority to create a creature like her current vessel.

The Monster God, that had the authority over all the monsters of Terra World, and the Ancestor God, the oldest and strongest god in existence in Terra as well as the one that bought Vhod and the other 6 humans from Earths and turned them into the 7 Original Demons for its own plans.

Reaching this conclusion, Rayel sighed in her mind and put the matter to the side, for even Vhod at her peak was incapable of touching the unfathomable Ancestor God. As such, Rayel moved her attention to her current environment, only to find something even crazy than her rare vessel.

A pearl-like glowing orb that gave the impression of being both fragile and dangerous at the same time.

A dungeon core. Something that could only be formed during the early stages of the formation of a dungeon - or so Rayel found on her memories.

Seeing the dungeon core, Rayel finally understood how her body was created, or better the condition and limitation used: dungeon master. A monster born from the raw energy of the dungeon core while sharing its life with the core, making so that the monster would continue protecting until it dies. This desire to protect isn’t different from an instinct to a dungeon master.

But things are different for Rayel, who could retract her consciousness from her vessel and manually control her body like a puppet or robot, though at the cost of an interval to her 'commands'.

She coldly assessed her situation and options, reaching to two paths. One, follow the scenario imposed upon her by those from ‘above’ and develop a dungeon from this cavern. Two… ignore the scenario and devour the dungeon core, regaining back her freedom and possibly gaining some power from it.

Smiling in her mind, Rayel discarded the first path and moved to the core, for she got controlled for too long as Vhod.

Skillfully controlling her body, Rayel expanded it and jumped at the core, devouring in one bite.

Naturally, the dungeon core reacted and tried to break free from her body, but before it could do anything, Rayel manifested her powers.

With the spiritual energy [Nightmare Spirit] created by Vhod, she suppressed the core inside her body.

With [Revitalization], a skill derived from the [Sloth] Sin that the controlled yet sane Vhod devoured from her companion when she was ordered to forced to kill the other demons, she used the energy leaking from the core to quickly close any wound produced by its rampage and recover her health.

And finally, using [Predation], derived from the [Gluttony] Sin, Rayel slowly processed the dungeon core suppressed inside her body, like a perfect example of a slime. And like this, Rayel passed a long period of time, slowly devouring the core until it ceased to exist and merged with her Slime Chimera body.

Under her will and traits as a ‘spiritual entity' from Vhod’s time as an Evil Spirit, as well as the influence of the [Nightmare Spirit], Rayel body changed in a way that it could manifest the best of her powers… not as a demon, monster, or evil spirit, but as a [Nightmare], a unique race that stood above the other creatures of evil and darkness like vampires, succubus, and demons by using its former status as an evil spirit as a foundation to its might.

Feeling the mysterious change that her body experienced, Rayel suppressed her eagerness to go out and rampage as much she could and adapted the plan laid by Vhod to her new capacities. She was well aware that despite having great growth potential, even more than in her time as an Original Demon, her current self is just too weak while the special ‘powers’ left by Vhod, required certain conditions to be used.

Not to say, that as a being with the power of [Lust], Rayel required lust energy acquired from her prey, a type of demon energy. Otherwise, her power and growth would be naturally suppressed as a side-effect of [Lust], forcing Vhod to abandon the plan of making her future self strong from the start and go all-out with cheat-level potential.

The greatest limitation that her current self has was the need of ‘vital essence’ in the form of life/mana/spiritual essence or divine power, as well as lust energy that she could interact thanks to the abilities of the [Lust] Sin that she inherited from Vhod, the original owner of it. This limitation originated from her existing as nothing more than a spiritual body that relies on different vessels to continue living outside of the reincarnation cycle existent in Terra World, meaning that even her current vessel as a Slime Chimera is something fated to be abandoned in the future, like an earthling that constantly changes their smartphones whatever time they see a new and better one.

Deciding that was time to start moving, Rayel used the [Shapeshift] skill, derived from the [Envy] Sin, and assumed the form of 3 dungeon core’s by using the records of the devoured one a base, before using the energy available in the simple and small dungeon where she was born as fuel to a series of spells before spreading a wave of energy aimed to attract the attention of any person or monster alike, and then, Rayel waited.

For the moment that she would fell on the hands of someone worthy of receiving her ‘grace’.

.

.

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Thanks to the explosion of an E-Rank dungeon in the West Region, many adventurers and nobles searched for the cause and any possible treasures only to exit with empty hands.

This continued until a group of lucky adventurers found what they judged to be 3 ‘dungeon cores’, an amazing item that could be sold for a bizarre amount of money thanks to the ability to either giving a new skill or awakening a sleeping skill of the person who used - different from the more common monster core, that could only be used for the user drain its energy for their cultivation. As the group couldn’t decide who would use them, they decided to sell the cores and divide the money, resulting in the cores being separated and wandering from place to place for a few years.

Mysteriously enough, the core failed to active or assimilate with everyone that tried it, that is, until a certain woman heard about it and decided to pay for a try, gaining the ability to control poison and even the [Great Poison Resistance] passive skill. The woman was a married Demon Hunter that followed her husband on her job.

Despite the woman assimilating the supposed unique dungeon core nothing in particular happened for months and before the woman knew, she herself pregnant with a baby, bringing happiness to their house. The couple asked for a time from their job for about a year and lived peacefully even after their baby girl, Rayel, was born - a name that suddenly appeared in numerous dreams of the woman.

After the mother and baby stabilized, the family's husband returned to work while the woman looked at the house and their child, continuing like that until the baby reached its 5º birthday, where the mother then returned to help her husband with her Demon Hunter work.

The family's peaceful life continued until the extremely cute girl crossed her 10º birthday when a terrible event happened, where numerous monsters invaded the town that had been peaceful for years without problems.

At that moment, no one doubted that the responsible for the catastrophe was the 'thing' sleeping inside the girl.

Glossary Time!

Passive Skills - divided into two types: those whose effect is always active and those that require a trigger to display the effect, for example, holding a sword or the will of the user.

Active Skills - requires the user to will for its activation with a vocal or mental input and in most cases, pay a price in the form of mana, stamina, spiritual energy/focus, or even one health.

Special Skills - while most skills have levels from 1 up to 10, some of them have no level, with their powers already being caped from just having the skill, making them a Special Skill.

Arts - they can be anything comprehended and displayed by the user at least once like a martial art-like technique, a magic spell-like Fireball, or an ingenious method of using one spirit.

Gifts - also called 'Supreme Skills'. Any kind of ability that was born/awakened or developed to the point of blending with the user's soul, becoming a core power of one being. According to Vhod - and now, Rayel's knowledge, there's 

Exists outside the ‘realm’ of Skills thanks to them relying mainly on one soul and will rather than body and energy, allowing them to even overwhelm skills with a higher rank than them in some cases.

Attributes

• Types of energies, forces, and elements that exist in the universe.
• Some examples are the 6 Basic Elements:
  • Fire, Water, Earth, Wind, Light, and Darkness.

Grade x Mastery:

• Abilities are ranked in two ways:
  • Grade, the level of the ability, how strong it is.
  • Mastery, the proficiency of the user with the ability, how well the user can use it.
• Grade follow the normal ranking system, from the lowest F, trashy or defective, up to S, the level of divine and legendary beings.
• Mastery is already different, with the ranks being ranked from Lv1 up to Lv9.
  • When an ability mastery reaches Lv10 is possible to rank up its Grade.