Dark Lord

About
Dark Lords (sometimes translated as "Demons" or "Fiends") are creatures conceived by one of the Gods to be the most powerful beings in the mortal realm, with the Demon King at the top of the pyramid of power. Unlike with the Demon King however, their personality doesn't suffer any direct change as a consequence of the transformation itself.

These extremely powerful entities are created out of ordinary creatures by consuming the blood of the Demon King. The process of turning into a Dark Lord may or may not alter its appearance. There are cases of drastic transformations while there's other cases of creatures not going through any change at all, and there is no common physical traits to visually identify them, to the point some Dark Lords look roughly the same as a member of their original race.

At any given time, only 24 Dark Lords (not including the Demon king) may exist, and female Dark Lords are infertile to ensure that this number never goes up. If a Demon King wishes to make more Dark Lords, it must kill off some of the existing Dark Lords to make space. This limitation in numbers was placed by the Gods to avoid the forces of the Monster Realm to grow so powerful that the conflict with the Protagonist Race devolves into a boring slaughter fest. Male Dark Lords are capable of impregnating other living beings, but this is an exceedingly rare occurrence and the child born from the copulation is not a Dark Lord but an empowered member of the mother's race.

Additionally, Dark Lords do not age, and unlike the Demon Kings, who only get their powers for 1000 years each, an ordinary Dark Lord would remain a Dark Lord indefinitely. They can be killed but this is typically an extremely difficult task, as they are the most powerful living beings in the world after the Demon King.

Despite the scary name, not all Dark Lords are destructive or evil, infact, quite a number of them are capable of compassion and sympathy, while some are completely apathetic or have no interest in violence. Even though the Demon King is a savage and vicious monster with nothing but hate for the Protagonist Race and Dark Lords are forced to obey his/her orders, that doesn't mean they have any personal dislike for humans or such, and quite a number of them are willing to help people in need, though some of them are highly destructive and/or sadistic. Overall, the actions and personality of Dark Lords are largely dependant of each individual member.

Powers
Those who become Dark Lords have their maximum potential increased exponentially. They are immensely powerful and even the weakest Dark Lords are on par with the strongest humans in history. They typically have either extreme physical or magical power (sometimes both), and they tend to have several unique and powerful abilities of their own.

Furthermore, all Dark Lords are covered by an Invincibility Field 100% of the time, protecting them from harm by ordinary means. No matter how strong an attack is, if the Invincibility Field is not broken first, the Dark Lord won't receive a single scratch. Currently, only the following may dispel or ignore the invincibility field to harm or kill a Dark Lord:
 * The Holy Katana Nikkou.
 * The Corrupted Sword Chaos.
 * The Guardian Hero of the World when at least 30% of humanity is dead.
 * Other Dark Lords (including the Demon King).
 * Devils.
 * Gods (including Angels and Holy Beasts).

Additionally, even if the Invincibility Field was pierced, Dark Lords are extremely durable creatures. They can easily take wounds that would be mortal for other living beings and they have high regenerative properties, allowing them to recover in faster periods of time than humans do. Usually, it is unthinkable for a human besides the Hero to even dare face a Dark Lord in a 1 on 1 combat, even for skilled and experienced warriors. Defeating a single Dark Lord is usually a very challenging encounter that requires a large group conformed by several extremely talented people, and that's assuming at least one of them has Nikkou or Chaos in their possession.

Powerful Magic Seals can seal a Dark Lord for a long period of time and is the safest way for humans to deal with Dark Lords. Magic by the mortals cannot directly harm or damage the Dark Lords, but it can isolate them in a secluded field. Some rare magic items may be able to temporarily restrict a Dark Lord as well. However, these methods usually work only on the weakest Dark Lords, as any moderately powerful is perfectly capable of rendering these mechanisms useless.

In the odd case that a Dark Lord is successfully slain, instead of simply dying, it turns into a glowing red pearl called Demonic Blood Soul. This crystalyzed gem is a Dark Lord's last mechanism for survival. If the Blood Soul is merely left alone, the Dark Lord will eventually be resurrected naturally, though the process takes several centuries and the period of time seems to vary depending on each Dark Lord. The Blood Soul can also be consumed by another living being. When this happens, there are two possible outcomes.
 * The Creature will overcome the will of the previous Dark Lord and become one himself, effectively replacing the previous one in the process.
 * The self of the original Dark Lord will take over and resurrect immediately, and the individual that consumed the Blood Soul will simply dissappear.

The Demon King can also re-absorb the blood soul back into the his/her body and it's the only way to permanently erase a Demonic Blood Soul. The safest way for humans to deal with them is by sealing them with powerful Magic, preventing it from reviving through natural means.

Hierarchy
Due to the powers of the Demon King in their blood, Dark Lords are unable to disobey the Demon King. Even if the Demon King who created the Dark Lord dies, the Dark Lord would still be absolutely obedient to the new Demon King.

Directly beneath the Demon King is the Supreme Dark Lord, a single individual that is elevated to a higher status by the Demon King. The current Supreme Dark Lord is Hornet.

Beneath the Supreme Dark Lord are the Four Elite, four Dark Lords that are older, more powerful and more experienced than most of the other Dark Lords. The current members of the Four Elite are Kayblis, Kesselring, Silky and Kamilla.

Dark Lords can   also  form and command a Demon Army, usually to attack large human countries, as they have absolute command over Monsters.

Apostles
Similar to how a Demon King may use its blood to create Dark Lords, a Dark Lord may give its blood to other creatures and create Apostles. There is no limit as to how many Apostles a Dark Lord may create, but the Dark Lords' power gets spread thinner as the number of its Apostles increases. Also, the more Apostles a Dark Lord creates, the weaker the control the Dark Lord has over them.

Like the Dark Lords, Apostles are immortal and have no limit on life span. However, they do not have the invincibility field and can be killed by normal means. The demands of their master are aboslute to them, and they cannot disobey. If the Dark Lord dies and the Blood Soul is consumed by another being, the authority of the Apostle moves along to the new Demon.

There is also another subset of apostles refered to as the Lesser Apostle. They are being that are not actually bound by the sharing of blood, but rather, a servant loyal simply by an oath of loyalty. They don't have any special ability for it.

Factions
Currently, for the first time in their history, Dark Lords are in a civil war. There are two factions of Dark Lords in conflict with each other. Since the death of Demon King Gi, the Dark Lords were split in two over how to deal with Little Princess Miki not desiring to rule as the new Demon King.

Hornet, daughter of Gi, leads the faction to follow the wishes of her father and bring peace to the conflict between human kind and the Dark Lords with Miki as the ruler.

Kayblis, the oldest and most powerful Dark Lord of all, desires to kill Miki and become the new Demon King himself. Majority of Dark Lords sided with Kayblis and joined his faction.

The Hornet Faction has contacted Miki and Kentarou many times, even befriending them. Protecting the Little Princess from Kayblis' assailatns is their highest priority.

Despite the fact the Kayblis Faction is immesely larger in size and power, it has conflicts within itself. Many of the Dark Lords follow Kayblis only due to common interest, and in fact despise Kayblis and his ways.

Both Factions also have thousands of monsters that sided with each faction depending on their individuals opinion on the matter.