~Ranks~
Rank refers to the strength and danger evaluation system of the Free Guild for Monsters, Adventurers, and other groups.
Both monsters and adventurers are ranked from F to A. Monsters who are in the upper echelon of their rank have a "+" attached while those in the lower echelon have a "-" attached. Grandmaster Yuuki Kagurazaka established this ranking system in place of the previous four-step 'Novice -> Beginner -> Intermediate -> Advanced' system.
After the introduction of the letter based ranking system, Novice was replaced with F, Beginner with E, and Intermediate with D. Meanwhile, those who were previously categorized as Advanced were split further into C, B, and A. Doing so distinguished the stronger from the strong. Thus, due to the introduction of the new system, the number of deaths due to fighting stronger than expected monsters greatly decreased.
The new ranking system is built on the inference that a party of adventurers is taking down a single monster of the same rank. For example, if adventurers are going to hunt a rank B+ monster, multiple rank B+ adventurers are needed (at least 3 people). If 10 adventurers with rank B tried to subdue the rank B+ monster, even if they were successful, there would surely be casualties. Furthermore, just because a sighting was confirmed doesn't mean that the subjugation can begin immediately. Normally, not many rank B+ adventurers stay at the frontier; the problem is that monsters appear too frequently.
Rank A- and above humans are considered "Champions" by Human countries.
Rank B and below adventurers aren't famous enough to be known outside their country's borders.
In the case of most monsters, the amount of magicules is the only measurement scale for obtaining a Rank. However, monsters with lower magicule storage like Necron, who should only be at the level of regular A-Rank, manages to reach Special A Rank for the standards of human adventurers by proficiency with the sword alone. For the higher ranks of monsters, a monster's level of threat is more important than its raw power. That's why Charybdis, despite having Disaster-class (Rank S) magicule capacity, is only considered a "Special A-Rank," since its lack of intelligence makes it nothing more than a mad beast.
The Ranks for Adventurers are decided by their proficiency, while the Ranks for Monsters are decided by their Magicules. Thus, monsters of the same Rank can have massive differences in power.
It should be noted, however, that this measurement system is flawed and there are many ways for someone to be actually stronger than their Rank suggests; for example, intelligent monsters can learn human "Arts" or possess Skills that grant them more effective battle power than a greater Magicule Capacity would grant. On the other hand, humans can become Sages or Majins and make contracts with Spirits. Otherworlder humans also have their own advantages, such as Skills (possibly even Unique Skills) or Magicule levels that regular humans can't achieve normally.
Threat Levels
For Rank A and above, monster ranks are evaluated based on their ability to threaten civilizations rather than just their individual magicule amount. There are 6 threat levels.
A Rank, also known as Hazard-class: A threat that could potentially cause widespread damage to a single town or region. Includes the Ranks A+, A and A-.
Special A Rank, also known as Calamity-class: A threat that could topple a nation's government, caused by the manoeuvring of high-level Majin and demons.
S Rank, also known as Disaster-class: Normally applied to demon lords. Small nations would have no chance against such a threat, and a larger one would need to expend all its resources to handle it. Being accepted into the Ten Great Demon Lords immediately warrants the newcomer to the "Demon Lords' club" to be considered S Rank.
Special S Rank, also known as Catastrophe-class: This applied only to a select few, most of which were established Demon Lords, as well as True Dragons, and reflected the kind of threat that no single nation could handle. It would require international cooperation to give the human race even a chance at survival.
- Source: Tensura Fandom (Rank) Strongly recommend visiting it to really learn more about the world of Tensura and how everything connects. Only placed this extract here because there might be new persons reading this book who have no clue as to how the Ranking system works.