The Sociopath: She's completely incapable of feeling anything, except pleasure at the suffering of others, and rage when her pleasure is taken away, or she's made to endure any kind of discomfort. Bewildering Punishment: Keryll didn't know his childhood friend, Lucia, was a Yandere, easily believed her lies that Minnalis had been bullying her, didn't know that Minnalis and her mother had been sold to slavers, and honestly has no idea why Minnalis hates him so much. As far as Minnalis is concerned, that is no excuse and only makes him guilty of Never My Fault. She arranges for a Karmic Death, having undead blame him for things he didn't do and torturing him until his mind breaks before she finally lets him die. Fair-Weather Friend: Minnalis's human father seemed to be a loving one for most of her life. But she inherited her beastman mother's race in a Fantastic Racist village. When her race was exposed, he abandoned them and let them get taken by slavers.

All for Nothing: Lucia sold out her childhood friend (Minaris) as a beastman, so that she could keep Kirel (their other friend) whom she intended to marry all to herself. She spent the next ten years driving away any rivals and trying to win his affections. On what was supposed to be Lucia and Kirel's wedding day, Minaris returned and triggered a zombie apocalypse. In the middle of the fight, the vengeful rabbit girl revealed to the girl that betrayed her that she had not only already killed Kirel but destroyed his body, leaving behind no trace of his existence. Lucia could only scream in horror at the revelation that everything she had ever dreamed of had been taken away from her at the last second. Even Bad Men Love Their Mamas: Gender inverted on Minaris' part. Apart from Kaito, the only other person she genuinely loved was her mother Maryse. Minaris actually weeps tears of joy after taking her brutal revenge upon the citizens of her former hometown, knowing that her mother has now been avenged. Moral Myopia: They care nothing for the injustice and suffering they inflict others, as long as they can reap the rewards for their own selfish pursuits. If others can be used to take the blame for their more obvious crimes, they do so without a shred of remorse. The moment their own hideous crimes are inflicted upon them by Kaito and his friends, these wretched villains have the gall to cry foul, portray themselves as innocent victims and declare Kaito's acts of vengeance to be monstrous, unjust crimes worthy of a demon lord!Revenge by Proxy: Even though Lilia hasn't done anything to him, directly, he still has no issue torturing her, because she was an accomplice to the scheme to bring Kaito to the new world, resulting in the death of Shiori and the rise of the "Transcenders" cult and all the nastiness that came from that.

Face of an Angel, Mind of a Demon: She's got a powerful air of "innocence and elegance" about her, but she's sadistic, sinister, and supremely racist to the core. It takes four years in the original timeline for Kaito to realize it, and he hates himself for it. Love Makes You Evil: Pretty much Yumis's motivation. As the only legitimate child, her parents expect her to produce an heir. Due to her love for one of her maids, she is reluctant to grant their request, but she genuinely loves them and still wants to make them proud. Her chosen solution was to make them proud in another way, by creating a magic tool that would be widely recognized. To produce this tool, she murdered countless innocent people as experimental test subjects. As a result, Kaito's revenge against her mostly consists of Revenge by Proxy. The Princess took a great deal of pleasure in telling Kaito that everyone he ever cared about was killed by the Summon Everyman Hero spell they used to bring him there. Our hero spent many months, even years, running away from said “good guys” as he tried to survive whilst he realised his personally unforgivable mistakes towards those who truly believed in him - such as, believe it or not, the demon lord - compared to how well he treated all the people who exploited, betrayed, and abused him (whom he trusted, ironically).Asshole Victim: Each of them is guilty of discrimination, enslavement, betrayal, or a combination of the three (usually all of the above and worse). Not only do they deserve the hell Kaito puts them through, if not worse, seeing them utterly broken and losing everything they care about is cathartic. That's how despicable they are. Yumis, who betrayed Kaito and her half-sisters for the love of her parents and her maid, ends up a victim of Revenge by Proxy before getting slain by the ones she betrayed.

Never Found the Body: Technically, his body is found, but it's so decomposed as to be unrecognizable. Sympathetic Murderer: His revenge targets are so despicable and have put him and his companions through so much crap, that the audience actually looks forward to seeing him end them. Earn Your Happy Ending: After so much pain and suffering he went through; he finally gets to put an end to all his enemies and gets to return to Japan along with Minaris, marry her, and start a new life with the woman he loves. Dark Fantasy: The fantasy world in this setting fits in with some of its dark aspects with all races being supremacists to each other and the fantasy hero being betrayed and turning revenge. It is saying something that the closest person who is truly heroic is the supposed demon lord.Entitled to Have You: To Kirel. There is no act of violence she'd overlook to make sure he marries her, and nobody else, both in the past, and in the present. Although the horrific betrayal and exploitation he suffered from his so-called companions in the original timeline crushed just about every virtue he had underfoot, he still feels guilty towards all the innocents who were caught up in their villainy. As such, in the current timeline, he does his best to make sure such evil does not go after them again, though this does have limits. Keryll easily believed Lucia's lies that Minnalis had been bullying her. Minnalis convinces a bunch of undead that everything wrong in their lives is his fault. Cannot Spit It Out: She refuses to as she knows that Kaito still holds a torch for Leticia and confessing now would just lead to her being rejected.

Torture Technician: At every free moment, they bounce ideas off of each other to see what would be the most effective physical, psychological, emotional, or all of the above, method to make their victims suffer. The sword-form [ big fleshy sword with a vivid flesh color] 『Employ』 state in use, rather than the human-form 『Released』 state. The Deadly Sin series, which is formed in the form of a sword, can be used without chanting, and has no demerits, like the other Spirit Swords However, it possesses no outrageous ability and compelling force like the Spirit Swords that takes a human form in its 『Released』 state, and can only use its ability on a lower scale. A power that loses its might as a trump card in exchange for convenience. However, what is important here is that the two people in front of me know about the convenience and the power of the human form in its 『Released』 state. This Is Unforgivable!: She will never, ever forgive the "Transcenders" cult that murdered all her friends and family who weren't killed by Kaito's summon, and keep trying to kill her and Yuuto, thinking this will somehow whisk them away and make them "heroes" in another world.

Pay Evil unto Evil: Combined with a A Taste Of His Own Medicine. His primary method to break his victims down is to put them through, as closely as possible, everything they've done to others, including himself. Only once they've lost everything they care about, does he bother to kill them. There Are No Therapists: Truth in Television, seeing as part of the story is in modern Japan that treats any and all mental illness as a moral failing. Thus those who survived Kaito's summoning are left to their own devices and those who are Driven to Madness by the unflinching workaholic Japanese culture jump on the chance presented to try and escape to another world, regardless of how much blood they have to get on their hands. Hoist by His Own Petard: Invoked. Kaito asks Minaris to hit him with a poison designed to feed off his mana. Being a mage, his mana is very high, and the poison becomes more potent the higher someone's mana is. Minaris is all too happy to comply after this twit threatened her with "friendly fire."