The protagonist of this work. A member of the Black Flame Magic Dragon race and the top graduate of the Demon Lord Academy. For unknown reasons, he regressed to the day of his graduation ceremony. At the event where he was supposed to swear to respect and faithfully follow the 'Demon Lord's Standards' as the top graduate, he declared that the standards were trash, causing his treatment to plummet from honor student to dropout instantly. Since the benefits for top graduates were only available to those who followed the standards, he received no support. However, he preferred it that way and began his invasion from scratch with only his secretary, Gordon, while thoroughly ignoring the Demon Lord's Standards. He possesses the characteristic arrogance of the Magic Dragon race. Unlike other Demon Lords, he has zero respect for the Demon Lord's Standards. To Berze, they don't exist, and he uses them freely only as bait to lure others.

The heroine of this work. The first person kidnapped by the protagonist. The protagonist intended to kidnap the 13th Princess, who had the least influence and interest. However, he kidnapped the 1st Princess of the Hilderan Kingdom, who was the first in line for the throne and the designated successor. The reason the protagonist didn't realize this was that she was wearing a ring that hid her magical power. Berze knew there was a genius elementalist among the Hilderan royalty, but since he was so careless, he didn't even know the 1st Princess's face... Fed up with kingdom life for various reasons, she decides to use her kidnapping by Berze as an opportunity to enjoy freedom. She successfully contracts with an Elemental King through high-ranking spirits and even participates as a combatant, eccentricly calling herself the 'Dark Elementalist of the Four Heavenly Kings.' Because she became an ally so naturally, Berze forgot to turn her into a thrall. Others try to set aside their prejudices, and while they realize Hillon is Berze's pawn, no one can imagine Ernian joined Berze voluntarily until they see it for themselves. Her goal isn't just betrayal; she aims to reverse-train Berze and eventually lead him toward a relatively moderate path of conquest. Addicted to the efficiency gained from local cooperation starting with Ernian, Berze begins to persuade and take prisoners whenever possible, to the point where he hardly keeps any monsters in his tower.

The secretary assisting the protagonist. He was the top student of the Demon Race Training School and was assigned to assist the protagonist, the top graduate, according to Demon Realm regulations. He was initially very proud, but after the protagonist treated the Demon Lord's Standards as trash at a public event, he was forced to follow him to the dimension of Arein. As a secretary, he has many complaints about Berze's actions. Nevertheless, he is a loyalist who carries out Berze Deias's instructions perfectly. After seeing how chaotic the dimension of Arein is, he comes to understand why Berze ignores the standards and suggests appropriate measures to solve Berze's problems in the latter half.

A successful hero based in Hilderan who has already slain one Demon Lord at the start of the story. Before gaining fame, he was evaluated as being more skilled in politics than in actual combat. Among heroes who usually don't hide their eccentric personalities, he is someone who cares deeply about image management. In other words, he has a two-faced personality. When Ernian is kidnapped and other heroes boycott the kingdom's request for subjugation because the pay isn't as good as going to Erzest, he volunteers, seeing it as an opportunity to gain fame and influence in Hilderan.

An elf from the Maple Tribe. She was enslaved by humans, but the protagonist buys her to use as a spy, exploiting the perception that elves are good. Initially, she did not trust the protagonist, but after he used a 'Standard Hook' he didn't even mean, she began to trust him slightly and eventually entered into a contract.

The 3rd Princess of the magic kingdom, Akhan. She is technically a sub-heroine, but she is overshadowed by Ernian. She is a butchering expert obsessed with chimera research, constantly busy dissecting monsters and Demon Lords to obtain materials for her chimeras. Even among the formidable 'crazy princesses' in the story, her personality is bizarre. From the King's perspective, she is practically an outcast, but it's less about a lack of affection and more that he has given up because Lavinia is uncontrollable. Despite this, she is a popular figure in her country as the leading authority on chimerology.

A typical rookie hero who has skills but no track record and is hungry for fame. Originally, she had nothing to do with Berze, but while caught up in a conflict involving Granada, she was targeted by Berze, who was traveling outside because of Ernian.