The Monster Classification is a ranking system that defines the level of power for all ayashi. Certain attributes including physical strength, level of yōki (demonic energy), and other latent talents contribute to an individual's rank, though no criteria has defined the level of power for each category. The system largely sets on individual basis, however certain Ayashi races are presumed to have all members in a single class level. Only 2 categories have been mentioned: S class monsters and the A class monsters.
S-Class
The highest class is the legendary S-class. These monsters are the highest order of ayashi, the elite, the most feared. All S class monsters have demonstrated abilities that completely overwhelm other ayashi of lower rank. Only those with the most talent and ability can become S-Class. To go against one without superior planning, numbers, and luck is paramount to suicide.
While largely on an individual basis, there are a few species that put them automatically in the S-Class range, though they are few. They include Werewolves and Vampires. Some races such as the Yōko, Siren, and Raijuu come close to S-Class but still depends on the individual.
Each species possesses common abilities that contribute to their ranking but what sets them apart are the unique or highly-specialized set of abilities that principally make them known as being the paramount embodiment of a specific quality. These qualities can be strength (Vampire), speed (Werewolf), and any special abilities that individuals have gained to become S-Class.
Though they can shapeshift like all other monsters, be it a human appearance, a standard baseline state (their true state) or a more specialized, advanced configuration is often if not always more dramatic and "refined" than the forms of non-S-Class monsters. This can be seen in the fine-tuned, human-like appearance of a Vampire, the muscular, lithe physiques of the Werewolves and the sharpened, emblemed, sleek, and fire-covered forms of the Youko in both of their physical states.
The most powerful being in this group, the Vampire, is a species who's innate abilities put them at the top of the top class on principle. They have the special ability to convert their demonic energy (which is also known as yoki) directly into continuous, "pure" strength and are able to sense the presence of other Ayashi by waiting for the presence of their demonic aura. They also possess healing abilities that are so effective that they are considered immortal and can shapeshift into any conceivable form, though this form is entirely shunned due to the Vampire's innate narcissism except for one Kahula Shuzen who transforms her arm into very sharp blades.
To top it off, they have what is called 'Shinso Blood'. It is the ultimate upgrade to any vampire. It ramps up the healing ability of any vampire to near impossible speeds and exponentially raises their strength and speed. Only a few have this blood. One is Akasha Bloodriver (mother to Moka), Alucard, Moka (though it is probable the Shinso blood has been sealed away with her Seal), and Tsukune (through transfusion and becoming a true vampire).
Falling directly underneath them is the Werewolf, who is the only monster known to be able to readily challenge a Vampire in combat. While not as physically strong, they have more than enough speed and agility to compensate. Having both equal and greater speed than a Vampire, Werewolves can strike, move and operate with sufficient speed, intensity, force, and precision that they are often considered by the Vampires themselves as their mortal enemy.
Under the ability-enhancing light of a full moon, their abilities come out at the best. Speed and endurance both spike along with a feral-like ferocity. When the full moon is out, the Werewolves are at their deadliest.
Dark Lords
The Dark Lords are the highest ranking available to a monster, though it is more of a title than rank. They are the most powerful of all the Ayashi in the world. Though their species vary, Akasha Bloodriver being classified as a "Shinso" Vampire and Touhou Fuhai a Yasha, their skills and power are undeniable. No one knows if the title was given or self-imposed the title but three individuals kept that title for fighting and defeating Alucard, the oldest vampire (and presumably the strongest), giving them a rank above S-Class. Only the strongest of monsters or those with a suicide wish will take on a Dark Lord.
- Akasha Bloodriver (Head Of The Dark Lords): Due to the Shinso blood flowing in her veins Akasha has near instantaneous regeneration abilities that allow her to heal throughout all her battles. She is a powerful opponent, one said that when becoming serious that nothing could beat her. Her strengths are equal with her healing abilities allowing her to defeat immortal opponents such as Alucard. As said by Touhou Fuhai, Akasha is titled Nosferatu.
- Mikogami Tenmei: The current Headmaster of Yōkai Academy, he possesses the Rosary of Judgement, a powerful artifact that can create barriers. He possess powerful sealing skills as he was able to seal the Ghoul nature inside Tsukune with a Holy Lock, something that not everyone can do, though the extent to his skills is not known. It is presumed he has more skills than just creating barriers and seals.
- Touhou Fuhai : A yasha who excels at creating and performing seals. He was the one who originally invented the Hougetsu Jigen-Tou and a several other high level seals such as Moka's Rosary and the BakuRyujin, the seal that obliterates dozens of monsters in one hit. He seems to be dying as he reverts to a shriveled form of himself as to conserve "what little life-force he has left.".
- Issa Shuzen: Issa is a Dark Lord in the anime only. In the manga, he is the lover to Gyokuro and Akasha as well as the father to Moka and her sisters, Akua, Kahlua, and Kokoa. His only appearance in the manga is when Tsukune, Mizore, and Fuhai Touhou are pulled into Moka's Rosary. Not much is known about his abilities other than his natural Vampiric traits and abilities.
Known S-Class Individuals
Vampire:
- Alucard
- Issa Shuzen
- Akasha Bloodriver
- Gyokuro Shuzen
- Akua Shuzen
- Kahlua Shuzen
- Kokoa Shuzen
- Moka Akashiya
- Tsukune Aono
Werewolf:
Yōko:
Presumed S-Class Individuals
A-Class
A Class is the ranking just under S Class. While not the strongest, A Class is still nothing to laugh at. Many have highly specialized skills and is also largely based on the individual's skill rather than species. Because it isn't as exclusive as S Class, there are a wider variety of individuals that belong in this category.
There may be races that are automatically included in this ranking. Species like the Yōko, Siren, Raijuu, Succubus, and Yuki-Onna have the distinct possibility but nothing has been announced or confirmed inside the Rosario Universe.
In addition to being these second strongest class, A-Class has a variety of abilities that range from magic (Witches), summoning (Yasha), fire (Yōko), lightning (Raijuu), ice (Yuki-Onna), mind magic (Succubus), sound, (Siren), and/or brute strength and size (Cyclops, Frankenstein). Some have more than one skill such as Yukari who can use magic and summon.
Many individuals have multiple traits to boost their class to the vaunted S-Class like Raika (a Raijuu) who has lighting, speed, and strength. Or like Kuyō (Yōko) who has worked and trained to gain his S-Class status using fire, speed, strength, and multiple transformations.
They, like their stronger S-Class counterparts, may have additional transformations. This may be like the Yōko's ability to have a separate battle form something that hasn't been revealed yet.
Known A-Class Individuals
Succubus:
Yuki-Onna:
Witch:
Monstrel:
Siren:
Yasha:
Frankenstein:
- Unknown Student
Cyclops:
- Unknown Student
Jorougumo:
A-Class Individuals
- Wong Fei-Hung (Yasha)
- Wong Tim-Tim (Yasha)
- Ran Otonashi (Siren)
- Ren Otonashi (Siren)
- Rin Otonashi (Siren)