Demon Lord (魔王 maō, lit. "Demonic Monarch, Evil Monarch, Magical Monarch") is a term used in two different fashions, either as a Monster class or as a social position. In general, it refers to the strongest or highest-ranking among Monsters, however, that is not an absolute rule for most definitions and there are various examples of beings who are not Monsters that are recognized as Demon Lords by societies.
Despite the foreboding name Demon Lord, not everyone who holds this title is of malicious intent; though the fact they are immensely powerful may be the root of such beliefs. Thus Ramiris and Milim's childish behavior and Rimuru's kindness and generosity catch monsters, humans, and other species unfamiliar with them off guard.
Demon Lord as Monster Class
High-level Majin (上位魔人 jōi majin) at Hazard-class or Calamity-class, are not considered Demon Lords and they usually either serve as Lieutenants of Demon Lords or aim to become Demon Lords themselves one day.
Sub-Demon Lord Level (準魔王 jun maō, lit. "Quasi Demon Lord") refers to High-level Majin or beings of equivalent power on the lower end of Calamity-class. Individuals like Phobio and the other Beastketeers are considered as such.
Demon Lord-Level refers to individuals who have fulfilled the strength and Magicule requirement of a Demon Lord Seed, but might not have necessarily fulfilled the other conditions yet. They are usually ranked on the higher end of Calamity-class, possibly even reaching the lower end of Disaster-class.
Demon Lord Seed
Demon Lord Seed (魔王種 maō shu, lit. "Demonic King Species") refers to those Monsters who have fulfilled the necessary conditions to be able to start the Harvest Festival. In terms of strength and Magicules, they are at Demon Lord level, i.e. from high Calamity-class up to low Disaster-class, but usually a Demon Lord Seed has the advantage over a Demon Lord-level High-level Majin, as the requirements for becoming a Demon Lord Seed are usually also useful in battle and would, therefore, tend to give the Demon Lord Seed an edge in such battle despite the magicule level being matched, though depending on the conditions the other party can still emerge victoriously.
Depending on the individual, becoming a Demon Lord Seed by fulfilling all the conditions to become one, might cause an announcement by the Voice of the World and a race-change, while for others neither evolution nor announcement occurs, though they are still Demon Lord Seeds regardless.
The reason some Monsters go through this evolution when becoming a Demon Lord Seed is likely due to their current species not being able to handle the power of one, as could be seen with the Orc Lord being confused and severely limited with his actions due to being unable to bear the power obtained through Starving Ones until he became an Orc Disaster who could handle the burden. Rimuru likely didn't go through any evolution because Slimes are innately a race close to Spiritual Beings, on top of which he got his Stomach sub-space that possesses immense capacities, so evolution wasn't necessary. It's unknown if those who go through such an early evolution also go through another race-changing evolution upon becoming True Demon Lords, or if they just gain the benefit of additional Skills and enhanced Magicule capacities.
Since Demon Lord Seeds are required to harvest human souls for the Harvest Festival, they require the ability to interact with and collect Souls of those they kill. It is unknown whether one of the conditions of becoming a Demon Lord Seed is being able to gather and/or interact with souls, or if becoming a Demon Lord Seed is what grants that ability. Regardless, it can be assumed that Demon Lord Seeds are definitely capable of gathering the Souls of those they kill.
The Harvest Festival (
During the Harvest Festival, the one ascending undergoes a transformation in which they can physically and racially evolve, and gain a tremendous amount of Magicules though the exact amount may vary depending on the individual. It is easier to gain new or evolve existing Skills during the transformation. There is also the potential risk of a significant change in personality.
Additionally, the subordinates of the one who ascends will also receive "gifts" in the form of more Magicules, new and evolved Skills and potentially even racial evolution.
True Demon Lord
True Demon Lord (真なる魔王 shin naru maō) or Awakened Demon Lord (覚醒魔王 kakusei maō) is one of the ultimate forms of existence, only below True Dragons. It is usually the pinnacle a Monster can achieve by means of evolution.
According to the Voice of the World, the title Demon Lord always refers to True Demon Lords, meaning that such an existence is approved and acknowledged by the World's Systems itself, while Demon Lord Seeds are clearly referred to by the Voice of the World as "Demon Lord Seeds" instead. The only reason the term "True Demon Lord" even exists is to distinguish them from Demon Lords Seeds more clearly.
It is extremely difficult to fulfill all the conditions to reach this ultimate form of Monster-hood. Even those who have lived for many eons are not guaranteed such status, either because they couldn't properly increase their strength or Magicule capacity, or because they failed to fulfill the conditions for Demon Lord Seed and/or True Demon Lord stage.
True Demon Lords usually Range from higher Disaster-class to Catastrophe-class.
Notable True Demon Lords
Those who are known to be True Demon Lords by the time of Light Novel Volume 12: Eve of War
Demon Lord as Social Position
Self-Proclaimed Demon Lord
Self-proclaimed Demon Lord (自称の魔王 jishō no maō) refers to any individual that proclaims themselves as such. There are no restrictions to this and even those who are not monsters can declare themselves as such. However, this usually has grave consequences depending on one individual's strength.
If the individual in question is just at the level of a high-level Majin sub-demon Lord, or even just at Hazard-class, one of the established Demon Lords will quickly get rid of them by either sending their own subordinates to deal with it, or even attack themselves, quickly eliminating the one who had a bad grasp of their own power and the power of the Demon Lords, or might even die to armies or adventurers sent from the human side before the Demon Lords even get a chance to act.
However, if the individual in question is at Demon Lord-level, or is even at the level of Demon Lord Seed or True Demon Lord, then that individual might be able to fend off the attacker, or even turn the situation around and kill the attacker in retaliation. If such a case occurs, rather than being enraged at the newcomer, the other Demon Lords will instead usually view this as a display of strength and even invite the newcomer to take the place of the defeated or killed attacker.
There are no concrete examples of self-proclaimed Demon Lords that have been killed off, but for cases where self-proclaimed Demon Lords managed to beat their attackers at their own game, there is Leon who defeated Kazaream 200 years ago, and Rimuru who killed Clayman, both of which were then recognized as Demon Lords and admitted into the Demon Lord council.
Regardless of the result, due to either being eliminated or proving their strength, usually, no one remains in the state of being a self-proclaimed Demon Lord for long.
Recognized Demon Lord
Recognized Demon Lord (認められの魔王 mitomerare no maō) refers to Demon Lords who have been officially recognized by the established Demon Lords to be one among their own. This can be achieved in two different ways:
- Being nominated by other Demon Lords to join the ranks and getting a majority approval.
- Self-proclaiming to be a Demon Lord and then proving one's strength.
Once a Demon Lord is recognized, that new member also becomes a member of the Demon Lord Council.
Demon Lord Council
Founded by Guy Crimson, the Demon Lord council is an organization where all the recognized Demon Lords gather. The number of members and the name of the council varied greatly throughout history, but at one point the maximum number of members was capped at ten and the name "Ten Great Demon Lords" became established. However, later the organization was restructured again during a Walpurgis Banquet, and so the resulting organization was labeled as Octagram by the "newbie" Rimuru Tempest.
The only condition required to join the council is to be accepted by its members or forcefully take a spot from one of them. Anyone who joins is automatically considered at least Disaster-class by humanity just for being a recognized member of the Demon Lord council, regardless of actual power, unless it's Catastrophe-class, in which case it's higher, of course. However, it's pretty much impossible for anyone other than Ramiris to join the council without being at least at Demon Lord-level of power. Furthermore, the Octagram has even higher standards since every member is already at least at the level of a True Demon Lord in power.
- Prior to the creation of the Octagram, a large part of the world's populace thought the power of a True Demon Lord was equivalent to that of a Demon Lord Seed, in part due to the most active Demon Lords of the current era among the former Ten Great Demon Lords having been Carrion, Frey, Clayman, and Roy Valentin, while the stronger and older Demon Lords chose to remain idling around, not bothering to show their true powers to the public for hundreds of years and instead preferred to act behind the scenes only.