Diablo | Reincarnated As A Slime Wiki


As I’m watching more and more anime, I really have to realize that there has to be a character named Diablo in every series featuring demons. Almost the same with Beelzebub or simply Maou. That’s not a drawback of course, but if you are talking about a character named as such, you have to specify it a little.

Diablo in TenSura is quite a sweet guy compared to most other entities named after the dark lord. If you are interested in his character or background, his relationships, and basically any fun facts, you should totally read this blog!

Table of Content

TenSura is an insanely popular franchise right now. Four different media are exploring this universe, including even a web novel! To make sure to not get lost in all the information, these articles summarizing its characters and events might come in handy!


Diablo Table

Character Information

Title: Primordial Demon Noir


Gender: Male

Species: Demon Peer

Age: 20,000+

Hair Color: Black

Eye Color: Gold

Nicknames: Primordial Noir

Rank: Disaster

Professional Status


-Butler Of Rimuru Tempest

-Secretary Of Rimuru Tempest

-Leader Of The Black Numbers

Affiliations: Jura Tempest Federation

                             Black Numbers

Appearances in ANIME/MANGA

Manga debut:

Chapter 67

Anime debut:

Episode 23

Light Novel debut:

Volume 5

Web Novel debut:

Chapter 70

Voice Actors

Japanese: Takahiro Sakurai
English: Damman Mills


Diablo looked like a real prince upon his first arrival. Well, it’s only expected that one of the strongest beings would dress like such. On the other hand, he had no intention of being snobby.

Besides his shiny dress, Diablo also had a bored look on his face. This feature was nicely balanced out by his emo hairstyle, which was plain black except for a few red and golden streaks.

After transforming into a Demon Peer and abandoning his Arch Demon looks, Diablo now tried wearing a butler uniform. We can safely say that it suits him better! His dignity didn’t shatter though.

His butler uniform is quite simple compared to his princely dress, but it’s still unique in a sense. His coat is slightly extended on the bottom, and Diablo likes to wear a piece of thin cloth tied as a ribbon tie around his neck. He also sports a red “belt” made from stringed-up decorative meshes.


Diablo is really as humble as one can be. Imagine that you are one of the seven most powerful demons, but you just bum around instead of utilizing your skills! Well, most people would do just as Diablo did.

But one day, after meeting a person worth your time, a real hit, you can get attached to them even if they are inferior to you. Diablo did that pretty easily, as Rimuru proved to be a great overlord for him.

Being mesmerized by Rimuru’s unique Soul, Diablo and the two underlings were delighted to work for their new boss. The other two even accepted the fact that they will be used to awaken Rimuru’s Demon Lord self.

After the protagonist found out that the demon he summoned was an Arch Demon, namely one of the seven primordials, he was damn grateful for the opportunity. That was the time when the former Noir received the name Diablo, which he used ever since. 

Diablo grew pretty close to Rimuru, and he protects his master in every way possible. Diablo likes to punish anyone who says one bad thing about Rimuru. Despite his somewhat aggressive nature, Diablo is composed and stoic.

Diablo uses every opportunity to show off his strength to Rimuru and to grow closer to him. Usually following every order to the letter, his actions rarely get sidetracked. Surely a great butler/hitman to have around!

Strengths and Skills

Diablo Magic Types

Magic Types

Diablo, as a high-level demon, is able to pull out some notable magical stuns. He is capable of using aspectual, fire type, and divine magic as well. 

  • Aspectual Magic:

o Creation Magic

o Barrier Magic: Anti-Magic Area

  • Elemental Magic: Fire Magic
  • Demon Summoning Magic: Summon Greater Demon, summon Lesser Demon
  • Holy Magic:

o Divine Miracle

o Disintegration, Multi-Stage Disintegration

Diablo Abilities


Diablo is an incredibly powerful guy, which comes as no surprise due to his primordial nature. As he is rather shy, his Disaster rank fades into oblivion. Diablo rarely fights, which is an accepted fact by most demons.

Unique Skills

  • Tempter

o Thought Domination

o Charm

o Solicitation

o World of Temptation

o Reality Exchange

  • Great Wiseman

o Thought Acceleration

o Chant Annulment

o All of Creation

o Law Manipulation

Extra Skills

  • Universal Sense
  • Multilayer Barrier
  • Spatial Travel
  • Demon Lord’s Haki


  • Pain Nullification
  • Physical Attack Nullification
  • Ailment Nullification
  • Spiritual Attack Resistance
  • Holy Attack Resistance
  • Natural Element Resistance


  • His name means “devil” in Spanish.
  • Diablo is a loner, which is why he doesn’t like having subordinates, and ultimately rejects the idea to create more black demons. Because of this, their numbers are the lowest among demons.
  • Rimuru named him after the Lamborghini variant, Diablo.
  • Diablo is really into being a butler.


The seven Primordials didn’t have official names except for the colors they were assigned to. The substitute names like Testarossa or Guy Crimson were just nicknames really, and their real identities were the French color names that each had.

Diablo was the same as the rest. His initial identity was Noir, meaning black. He wasn’t like the other Primordials in behavior either. Noir was a loner for the most part, as he didn’t take part in regular high demon action either.

Once he realized the fact that his power became so great that no one proves to be a real enemy for him anymore, Noir stopped pursuing power, despite the fact that he would have been able to evolve into a Demon Peer.

He was summoned once by Silver Wing in order to take out Shizue Izawa. During the fight, Noir had to realize that he can’t win the encounter, as Shizue had the Anti-Magic Mask, an item that could manipulate time itself, basically having the power of infinity.

Noir returned to the Astral World, and he became quite curious about that item. Once the mask was broken, it became the holding of Rimuru. Noir immediately thought that Rimuru was the “key” to the truth, as the mythical magic item must mean a great destiny.

He tried to get close to Rimuru as soon as possible, but he was left behind by his descendant, Beretta during a summon. After Rimuru summoned a demon for the second time, Noir finally hopped in with two of his underlings to help Rimuru out.


Jura Tempest Federation

After pledging loyalty to Rimuru, Diablo basically became a vassal of the Jura Tempest Federation. While the country may not have existed formally at the time, the foundation was laid down right when Diablo made friends with Rimuru.

Diablo is not only the secretary of Rimuru, but also an executive of the country. He does a great job at managing affairs, but of course, his rank there can’t be compared to some of the other higher-ups. 

Diablo became quite patriotic for the Jura Tempest Federation, and he makes sure to protect the realm with all his power. To maximize his effectiveness, he formed the Black Numbers.

The Cold War Situation

It would be also important to mention the hierarchy of demons at the time. While the members of the Octagram were the strongest Demon Lords, the frequent change of positions made it clear: the Demon Lords aren’t even demons.

Only Guy Crimson was a demon, the other seven were different species of monsters. When the ambitious Rimuru Tempest was accepted into their council, the balance of power became easy to understand.

Diablo quickly mobilized his subordinates and the other friendly primordials to enter his army. This meant that at their peak, the Jura Tempest Federation had four primordials serving under their flag. 

Guy Crimson convinced the rest of the higher-ranked demons to join his cause, and at the moment, all seven primordials serve one of the two most influential politicians: Guy or Rimuru.

Of course, this doesn’t mean that there is a war-like situation developing between the two parties. Rimuru and Guy are allies, and they have some pretty friendly relations with the other Demon Lords as well, but it is important to mention that everyone is aligned to a cause.

Black Numbers

This squad, formed by Diablo, is one of the most effective fighting forces on the continent. Diablo recruited hundreds of his descendants in the Astral World to show off his strength to Rimuru, but he also brought three other primordials with him!

White, Purple, and Yellow were named under Rimuru’s coat of arms, and they became the leaders of a battalion each in the Black Numbers. They could choose their own underlings. Now Testarossa, Ultima, and Carrera, as well as the other lower-ranked demons actually pose a threat to any enemy.

Diablo chose Venom as his right-hand man in the personal army. While he personally doesn’t like to fight, leading an army is a piece of cake for this veteran soldier.

Black Demonic Realm

This squad, formed by Diablo, is one of the most effective fighting forces on the continent. Diablo recruited hundreds of his descendants in the Astral World to show off his strength to Rimuru, but he also brought three other primordials with him!

White, Purple, and Yellow were named under Rimuru’s coat of arms, and they became the leaders of a battalion each in the Black Numbers. They could choose their own underlings. Now Testarossa, Ultima, and Carrera, as well as the other lower-ranked demons actually pose a threat to any enemy.

Diablo chose Venom as his right-hand man in the personal army. While he personally doesn’t like to fight, leading an army is a piece of cake for this veteran soldier.



Rimuru Tempest

Diablo was really interested in the overpowered magic item, the Anti-Magic Mask. When Rimuru managed to get a hold of the said piece of equipment, Diablo’s attention immediately shifted to the new owner.

Well, he thought of Rimuru as the only path to find the truth about their world. Diablo worked hard to get summoned by the protagonist, and when the time came, they became good friends quickly. 

Diablo Rimuru

Diablo did his job smoothly, and he even offered Rimuru his subordinates as sacrifices for the Demon Lord awakening ritual. Rimuru was so pleased that he named the previously nameless primordial Noir Diablo.

Diablo became not only the butler but also the friend of Rimuru. He formed the Black Numbers to strengthen the forces of the Jura Tempest Federation, and he always sought new ways to prove his usefulness to Rimuru.



This beautiful ogre (not Shrek this time, sorry) is Rimuru’s number one secretary, which angered Diablo for real. They had a fierce competition over the grace of the slime, but eventually, Shion proved to be a little better at her job. 

She is also one of Rimuru’s strongest fighters on her newly acquired disaster rank, but one could argue that Diablo is still stronger, and he could wipe away Shion if he took his battle seriously.

They both shared fanaticism for Rimuru, but even Shion admitted that Diablo would be able to complete the job more quickly and efficiently, as he was always ready for a new order.

Primordial Demons

Demons In General

Diablo doesn’t really care about what other demons think of him, but he has a few connection points with them still. His descendants are loyal to him, which isn’t surprising as Diablo didn’t treat any of the bad.

Testarossa, Carrera, and Ultima are quite indifferent to him, but they were willing to join the Black Numbers. Beretta is a different story for the day, but to keep it short, they swept away Diablo’s opportunity to meet with Rimuru the first time he was summoned.

His relationship with Guy Crimson is unique as well. While the number one leader of the Octagram is a primordial like Diablo, he gathered others of their kind to serve him. Diablo on the other hand, convinced the rest of the higher demons to join Rimuru instead, as he didn’t want to control anyone for real. Guy and Diablo had some minor disagreements in the past, but they show mutual respect.

Background / Synopsis

Rimuru used the corpses of 10000 fallen Falmuthian soldiers to summon Greater Demons. Unknown to him at that point, the main demon was actually primordial, and he also brought two underlings with him.

Called Noir beforehand, the demon did a great job at capturing Razen. When Rimuru was short on energy for his Demon Lord transformation ritual, Noir offered to sacrifice his subordinates in the process. 

They had no issue doing that either, as they were already pleased with Rimuru’s personality. After becoming a Demon Lord, Rimuru finally understood that his summoned demon was a primordial. He decided to name Noir, giving him his new identity as Diablo.

Diablo didn’t only change his name. His whole outfit and lifestyle shifted in mere moments. The changes focused on becoming a butler both visually and spiritually. This was compatible with Diablo’s personality, as this shy and humble primordial liked to help out others.

He got fanatical with Rimuru. Upon becoming a Demon Peer – the highest demon rank achievable by natural means, Diablo gathered his own little personal army called the Black Numbers

He searched for the most capable demons that originated from his identity as the Black Primordial. Besides the hordes of lower demons, he also convinced three other primordials to join forces with him. They were Violet, Blanc, and Jaune before receiving names.

This squad became the most devastating force in the country, matching strength with many foreign powers. Diablo also did his best to become Rimuru’s number one friend and comrade. They proved to be a good team over the years.

Diablo was later given multiple challenging tasks, but he managed to overcome any obstacle with both intellect and raw power. He wasn’t a fighter for the most part though. One of his jobs was to investigate Falmuth, to cripple its governance and economy in the process. Diablo completed the job without an issue. As we could quote the Quintessential Quintuplets: like the shadows, unknowable!

Voice Actors

JapaneseTakahiro Sakurai

EnglishDaman Mills


How do you feel about Diablo after this? I think he is a very fun character, despite not doing many fun things. He is a stoic and humble being, one who enjoys helping, or even serving others. Pretty small dreams for a primordial being, huh?

If you liked this article about Diablo, I insist you read our other summaries about anime characters, especially about the other members of the TenSura cast! You can also leave a comment here about your opinion on this blog!


[1] Reincarnated As A Slime Light Novel: Volume 5

[2] Reincarnated As A Slime Light Novel: Volume 6

[3] Reincarnated As A Slime Light Novel: Volume 7

[4] Reincarnated As A Slime Light Manga: Chapter 67

[5] Reincarnated As A Slime Light Anime: Episode 23

[6] Reincarnated As A Slime Light Web Novel: Chapter 70

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