Home » Anime & Manga » Mairimashita! Iruma-kun » (2024) Power of Lord Sullivan in Welcome to Demon School! Iruma-kun Explained

(2024) Power of Lord Sullivan in Welcome to Demon School! Iruma-kun Explained

Last updated on February 15th, 2024 at 04:26 am

Written and illustrated by Osamu Nishi, Welcome to Demon School, Irum-kun! is one of the most popular ongoing anime and manga series. This series follows the adventures of a human through the dark trenches of the demon world called the Netherworld.

Iruma Suzuki is a 14-year-old boy who, throughout his life, had to face many hardships thanks to his good-for-nothing parents. Since childhood, he had to work multiple jobs to meet the necessities of life. His parents were never there and were busy enjoying themselves, leaving our poor Iruma to fend for himself. Eventually, the same parents sell him to a demon named Sullivan.

Initially scared for his life, the Netherworld turns out to be a pleasant surprise for Iruma. Sullivan is nothing more than a doting grandpa, and the school he enrolls in, Babyls, has plenty of fun adventures waiting for him.


The demon world is a place where rank is everything. It is the source of the demon’s prestige and power. Lord Sullivan is among ‘The Great Three’ who possesses the second-highest rank of Tet and is one of the candidates for becoming the next Demon King, the Lord of Netherworld, a position that has been vacant for many years. The entire series is filled with highly powerful demons, extraordinary magic spells, and fight sequences. 

Today, we will be talking about the strong but deadly Sullivan. Despite being a major character in the series, he is still shrouded in mystery as he has yet to show his full power. He boasts a complex identity interwoven with a mysterious past. Let’s delve deeper into the enigma that is Sullivan.

Identity and History

We all know that Lord Sullivan is Iruma’s grandpa. But that’s not all he is. A towering figure over 180 cm tall, Sullivan is one of the most influential demons of the Netherworld.

He is the principal chair-demon of Babyls Demon School, a prestigious Academy known far and wide in the Netherworld. He is also a part of the Thirteen Crowns and the Three Greats. We know of his various titles, but the series deliberately shrouds Sullivan’s past in secrecy, slowly revealing bits and pieces throughout the narrative.

The Three Greats in Thirteen Crowns

Sullivan is known to be only one of the three demons alive (apart from Lord Belial and Lady Levi) who have reached or had the potential to reach the higher ranking of 10, a.k.a Yodh. This puts him in the position of inheriting the thrones of the demon king. However, he makes it explicitly clear throughout the series that he has no intention of doing so.

Back when Derkila was not missing and still in power, Sullivan was his right-hand man. In some aspects, he seems to be closer to Derkila than even Amduscias Poro, as it is hinted that there are some things he knows that Poro may not be aware of.

Hints suggest a sorrowful past that shaped him into the playful yet responsible grandfather figure we see today. There also seems to be some kind of secret behind why he is ranked 9 [Teth] when, in actuality, everyone believes his power is equivalent to 10 [Yodh].

When Atori attacked Babyls during the Heartbreaker arc, he was eventually caught by Sullivan’s dark aura. When Sullivan asked him about his intentions, Atori belittled him and mentioned how “Derkila himself said that Sullivan can never become the Demon King as he is cursed”. This cuts to a panel of a bloody Sullivan holding his face with Delkira towering over him. This means something happened to him during Delkira’s reign. Something sinister that cannot be undone.

Sullivan's past

As the series progresses, expect more details about Sullivan’s past and true identity to be revealed. These revelations will likely shape his actions, relationships, and overall character arc.

Personality and Relationships with Other Characters

Initially, Sullivan appeared to be just a silly old grandpa. He brought Iruma to the Netherworld as he was lonely due to Belial and Levi’s constant gushing about their grandchildren and deeply wanted a grandson of his own. He is exuberant, playful, and childlike.

Sullivan is an extremely loving and doting grandfather. Maybe too much so. He is impulsive and prone to excessive emotional reactions. If he thinks Iruma is ignoring him or he isn’t getting enough time with him, he cries and throws a tantrum about how much he wants to see him.


However, all this seems to be more of a playful facade. Moments of seriousness showcase his strategic mind and immense power. His mask slips whenever he believes Iruma to be in grave danger. Furthermore, his charismatic personality and strength are what earned him a seat amongst the Three Greats.

As one of the main characters, it is easy to discern his relationship with other characters in the series-

  • Iruma Suzuki: Iruma is a human child who has been adopted by Sullivan as his grandson. He is extremely affectionate and caring towards him. Iruma himself has to step in to prevent his grandpa from going too far when it comes to spoiling and showering him with gifts.
    Despite being so doting, Sullivan knows how to set lines so that Iruma can grow as a person, develop more confidence, and grow accustomed to the Netherworld. He greatly believes in his abilities and only steps in when he needs to.
  • Opera: Sullivan’s right-hand demon who also works as his servant and security demon. Sullivan took them in when they were a child. It is implied that Opera grew up in unfortunate circumstances and was helped by Sullivan during that time.
    Sullivan is seen to also dote on Opera especially in the past. Opera greatly respects Sullivan, and Sullivan depends on them to keep him on track and help to fulfill his duties.
  • Delkira: Before being a part of the Three Greats, Sullivan was Delkira’s servant and right-hand man. The two seemed to have a close relationship and were almost inseparable. Sullivan is one of the demons who is the most affected by Delkira’s disappearance. This is why he got extremely angry at Baal when he suggested replacing Delkira from the Thirteen Crowns.
  • Kalego: As the chair demon of Babyls, Sullivan is Kalego’s boss. Kalego hates Sullivan due to his childish personality and making his life harder than it already is. However, he too, acknowledges Sullivan’s strength and obeys his commands. Despite everything, Sullivan also trusts Iruma with Kalego.
  • Amduscias Poro: Poro was shown to be jealous of Sullivan due to how close Sullivan was to Delkira. However, it seemed that they had an amiable (?) enough relationship until he appeared in front of Sullivan to rescue Atori. Poro was able to convince Sullivan to let them go, but it seems that the next time they meet, they will be enemies.

Power of Lord Sullivan in Welcome to Demon School! Iruma-kun

As mentioned before, Lord Sullivan is one of the most powerful and influential demons in the Netherworld. He hides his menacing personality underneath his jolly and eccentric side. All the demons in the Netherworld think thrice before angering him. He is one of the most feared and respectable demons.


Despite being the only character amongst the Three Greats who is rank 9 [Tet] instead of rank 10 [Yodh], there are many instances throughout the series that imply that his actual abilities easily make him a Yodh as well. Lady Levi also told him to “give up and rise to Yodh already”. His aversion to do so may have something to do with the curse he possesses.

Sullivan hasn’t revealed the full potential of his abilities. Even his bloodline ability is unknown as of now. Most of the time, he is able to keep his power and emotions in check. But there are enough examples to show that he holds immense power and knowledge, which can be seen from time to time both in the anime and manga series.

Powers and abilities

  • High Magic Affinity and Power: Lord Sullivan is extremely powerful and holds a tremendous amount of power almost possessed by none. In episode 5 (season 1) and manga chapter 8, Iruma gets the’ Ring of Gluttony’, which instantly devours the magical strength of everyone present, making them weak in their knees. Only Lord Sullivan was able to quench the ring’s hunger for power, which did not have any effect on him, unlike the others. In chapter 39 and episode 19 (season 1), Iruma was able to defeat Kirio and save the school only by unleashing Sullivan’s entire magic power stored in the ring using the spell ‘Pandora’. It was a highly deadly spell that gives us a glimpse of Sullivan’s true magical powers.
  • Menacing Dark Aura: Sullivan’s offensive power seems to manifest in the form of a black mass with creepy eyes. In chapter 262 of the manga, he used it to imprison Atori and almost choked him but was interrupted by Poro. This fearsome aura is capable of paralyzing even the strongest of demons like Kalego and Opera.

Menacing Aura

  • Gravity Manipulation: He can manipulate the force of gravity and can make things or individuals float. In manga chapter 92, he used the ‘weight regulating spell’- FRACTAL to make Iruma float and also caught the shoplifter.
  • Time Manipulation: Lord Sullivan can manipulate time. He can either slow it down or fast-track it. In episode 19 (season 1), when the burning embers from the fireworks were about to hit Babyls, he slowed the time and, using his power, rerouted them to fall into the dark pit surrounding the school, thereby saving everyone present there.
  • Sharp Senses: When a powerful spell is cast anywhere, he can sense it. As seen in episode 19 (season 1), when Kirio’s magical barriers appeared all over the school, he was able to sense it while being hundreds of kilometers away from the school.
  • Teleportation: He possesses the ability to teleport, which can be seen in many instances both in anime and manga series.
  • Encrypted Speech: He possesses the ability to speak in encrypted speech, which can be seen in manga chapter 146 while he talks with Baciko revealing that Iruma is a human.

Top 10 Best Anime Production Studio
Image Source: animeukiyo

Must Read – Top 10 Best Anime Production Studio of all time Ranked

Presently, only this much is known about Lord Sullivan’s power. As the manga progresses further, the true nature of his power and his very reason to bring Iruma to the Netherworld will unfold. Due to its long list of silly and eccentric characters, this series is a must-watch. It makes you laugh out loud from time to time and keeps one on his feet thinking as to what will happen next. Only time will tell what tumultuous future lies ahead for Iruma-kun in the eccentric world of demons.

The last main arc of the manga, the Deviculum and post-Deviculum arc, had Sullivan and the rest of the Thirteen Crowns on their toes. What with the whole whirlwind at the Deviculum and the aftermath that almost led to a war between the heroes and the Crowns, Sullivan was extremely busy. Thankfully, Iruma’s help and support were able to give him enough clarity to make the most important decision.

The series is ramping up, and we cannot wait to see how Osamu Nishi spins the story of Sullivan and the rest of the cast in the future!

Follow us on Twitter for more post updates.

Also Read-