Four Holy Gal Monsters

About
The Four Holy Gal Monsters (聖女の子モンスタ, sei onna no ko monsutā) are a quartet of Goddesses conceived during the creation of humanity. They were designed as the progenitors of the 3rd Generation of Monsters, the race created by the Gods to serve as the antagonistic force of the Protagonist Race; serving the Demon King and Dark Lords.

Prior to the 3rd Generation, a handful of specific sub-races such as the Shellfish and the Chasoba were created but, during humanity's inception, the Gods opted for a more creative approach and decided to craft four Goddesses. Unlike other deities, these four would live in The Continent and serve as the the "mothers" of all monsters. Their role is to wander throughout the land looking for remarkable individuals to mate with and give birth to a powerful new monster species. Over time they conceived countless sub-species, known as Guy Monsters and Gal Monsters, who would in turn breed with each other and continue to expand the genetic pool of the antagonist race. The result millennia later is of an extremely wide variety of monsters, providing a colorful and diverse array of creatures inhabiting the world of Ludo-Rathowm.

On present-day, these four are considered legendary albeit mistakenly registered as Gal Monsters by humans due to their similar visual traits and nature as mothers of monsters, though certain monster-loving groups like the Angel Army worship them. They are similarly revered by Monsters, who consider breeding with one of the Four as the ultimate form of pride and happiness. Male and female monsters can breed as many times as they desire but the child will always be of the race of one of their parents. It is only the Four Holy Gal Monsters that can give birth to a new species as they see fit, giving them a power to create new lifeforms in the world that is inaccessible to any other creature or even most members of the Gods Hierarchy. It is worth mentioning that while the Four Holy Gal Monsters are directly or indirectly responsible for the conception of all Guy Monsters and Gal Monsters, the label of "monster" given by humanity encompasses a larger collection of creatures, which includes Insects, Holy Skeletal Fighting Marshal, some Devils, among others; none of which were birthed by the Four Holy Mothers.

The Holy Gal Monsters' primary function in the world is to continue giving birth to new species of monsters, leading them to wander around looking for potential mating partners. Unlike Gal Monsters, who can only breed with Guy Monsters, the Four Holy Monsters can breed with any living being (even other females). Their usual partners are monsters but they are open to any other race that strikes their fancy in one way or another. The most common method of producing offspring is through conventional intercourse but it is not strictly required. The Holy Monsters are capable of birthing a child with a simple genetic sample of their partner, like saliva or hair. The process is extremely fast, as they will lay an egg shortly after and the new creature will be born after only a couple of weeks. However, the childbirth will drain the mother out of their power, mutating into a weaker form to preserve power and their appearance changes into a childlike one. The time that it will take them to recover varies based on a number of circumstances but it typically takes about 5 years, though it could be much shorter as well. Once they fully recover they transform back into their adult appearance and become fertile again. In theory, they could stay in their adult forms for as long as they wish but in order to ensure that they would carry out their duty, their creators implemented a failsafe system. If they spend a certain amount of time without mating after reaching their adult forms they will enter their estrus period and get a strong urge to breed. Initially, the feeling is very weak but it intensifies the longer they wait. When this happens they will typically mate with the strongest being in their proximity.

Beyond their purpose in spreading new monster species to the world, the Holy Monsters are in possession of powerful and unique abilities that are exceedingly rare in the continent. For example, Housesnurse is capable of manipulating the earth and bend it to her will while Serachrolas has time-controlling abilities that exceed human comprehension. When they are in their weaker forms these abilities are more limited but by no means any less impressive. In their adult forms they are also capable of using all their power to perform a single extraordinary miracle, such as Wenlina's ability to revive the dead. Doing so will deplete their power entirely however, forcing them to enter their childlike state immediately.

In spite of their position as the mothers of monsters, they are neither friendly nor antagonistic to any race in particular and remain mostly neutral to the world's conflicts. While they have a role to fulfil as a part of nature they are very much independent entities, with their personal opinions, tastes and dreams. They might side with humans or monsters based on their personal desires, or remain completely indifferent and continue travelling with their own interests in mind.