D

D is an enigmatic, high-ranking god, who is also one of the administrators managing the System of the other world that the reincarnations end up in.

Appearance
For the majority of the series, D has intentionally hidden and concealed her identity and appearance, preferring to communicate to characters in the series indirectly either using a summoned smartphone or via telepathy. She is typically depicted, visually, in the manga, as a female figure with at least shoulder-length hair shrouded in the shadows with a devilish grin.

It is only in volume 9 of light novel do readers get an accurate description of her appearance. D has the appearance of a high school girl with waist-length, straight black hair and eyes of various colors (includes black, gold, and red). Her normal outfit consists of a school uniform and a pair of glasses (LN — other sources may differ).

To Sariel, she appears as a girl one step short of being an adult with an expressionless face that makes one think of bottomless darkness.

Personality
"I wish you'd phrase that a bit more flatteringly. You could say that I'm malice incarnate, for example."

- D

D cares more for her own personal amusement than anything else, but she's described to speak in a voice devoid of emotions. She is a playful self-proclaimed “Ultimate evil god”, and most of the time states that she does things simply for entertainment.

D is described as immensely sadistic, seeing as she stated she enjoys watching and toying with Kumoko as she went through hardships to survive in the Great Elroe Labyrinth, and was particularly pleased at all the times she nearly died. The extent of her sadism seems to extend to tormenting entire worlds, like the choice to use the long-winded System to recover the planet despite the ability to do so instantaneously.

Background
Very little is known about D's past. According to herself, she will continue to live until the end of the universe; so it can be assumed that she is as old as creation itself. She has also been stated to be the manager of the Underworld, which seems to involve overseeing the universe's circle of death and reincarnation. According to Güliedistodiez, she also fought the ruler of the True Dragons, the Dragon God, some time in the past and managed to wound it. Eventually, however, D grew tired of her duties and hatched a scheme to get out of her job and play at being a normal high school student on Earth under the alias Hiiro Wakaba.

Great Elroe Labyrinth
D was first indirectly introduced as a silent figure who was spectating the adventures of the main character and enabled the creation of Kumoko’s Wisdom skill after hearing her short rant in the labyrinth. She later intervened and gave a brief introduction about herself to Kumoko, when another administrator tried to investigate Kumoko after the death of a fire dragon.

She appeared later again using a smartphone to congratulate Kumoko for evolving into a Zana Horowa, a first of her kind unique spider monster that has an innate immortality skill. It was also at this time, D divulged some information to the reason behind Kumoko's reincarnation into the world. Revealing that she is the person responsible for bringing the reincarnations into the other world. Furthermore, that she had indirectly caused their demise, as the mysterious explosion that occurred at the beginning of the series was an attack from the other world at her. The previous Demon Lord and Hero using combined dimension magic.

Hence, D decided to collect souls of the unintentional victims, and equip them with the mysterious n% I = W skill, which gives them Level Up regeneration and integrates the class and Ms Oka into the system. She also gave each student a custom Skill according to her perception of them and reincarnated them into species that best matched the wavelength of their souls.[1]

It was later revealed she is also responsible for the creation of the System, a complex planetary-scale conjuring that allows the inhabitants of the world to use skills and helps with the usage of magic. She obliged the request of Güliedistodiez and created the System as a way to help the planet's inhabitants gain the energy needed to restore the planet on their own. The System itself, though, is a double-edged sword that was implemented in part due to her curiosity and sadism.[2]

Relationships

 * Kumoko
 * D views Kumoko with a sadist perspective, taking enjoyment and amusement in seeing her struggle for survival and beyond. While she is not considered the series’ main antagonist, she has on occasions both directly and indirectly placed obstacles in Kumoko's path, never making it easy for Kumoko to accomplish her goals. D has maintained a near non-interference policy to the other world and newly arrived reincarnations as she is considered an outsider though she is quick to break her stance if her actions will result in more entertainment. D can be considered fond of Kumoko, after learning about her constant struggles and near-impossible survival in the harsh dungeon. She has given Kumoko numerous minor assists in her journey, such as granting Kumoko's request for a new skill, Wisdom; granting her the title, Champion, and giving her hints about the future.


 * Güliedistodiez
 * Güliedistodiez or Gülie for short is a fellow administrator of the other world. He is considered an acquaintance and an indirect subordinate of D. Despite being the original creator of the system, D left the heavy responsibility of maintaining and troubleshooting the System to Gülie. Despite the planet technically not being under D's jurisdiction, D has left him a few restrictions, that can be seen as hampering his abilities in controlling the planet. While Gülie is grateful for D's assistance in creating the system, he is also annoyed by D's constant interference in the other world's affairs.


 * Sariel
 * Despite being fellow administrators, D and Sariel do not share a friendly relationship. While Sariel's animosity is mostly instinctual, due to her being an Angel, D dislikes her for more personal reasons, viewing her and her entire race as “muscle-heads”.


 * Feirune
 * It is implied that the reason Fei was reincarnated as a Wyrm — a species D looks down on — is because she took issue with how she treated Wakaba Hiiro in their past lives.

Abilities
D is arguably the most powerful character in the entire series, with the only other possible contender being Meido. According to Güliedistodiez, she is the strongest god, whom all others actively fear and avoid. However, the sheer scale of her power also makes her full strength nigh impossible to measure, though Shiraori believed she could destroy a planet in its entirety with energy to spare. Even whilst placing 150,000 status ailments on herself, she was able to defeat the combined forces of Ariel and Shun's parties without a scratch and was only “defeated” with Shiraori's scythe, an item D herself created.

Conjuring

 * Dark Aura: The mere act of using conjuring makes D give off a sinister aura that frightened even Shiraori.
 * System: D has displayed the greatest feat of conjuring in the series: creating and designing the highly complex “System” that governs the giving of skills and stats of the world with seemingly little effort. Holding the position of “Senior Administrator”, D can also freely alter it as she pleases.
 * Skill Creation: As the creator of the System, D can create new skills and titles on a whim, being personally responsible for some of the more “game breaking” ones.
 * Granting Privileges: As the Senior Administrator, D can give administrative rights to others, such as Güliedistodiez and Sariel.
 * Counter-Measure Resistance: D's conjuring is so strong that it was completely unaffected by Potimas' anti-system barrier.
 * Dimensional Manipulation: Much like Shiraori, D can freely manipulate space. She primarily used this ability to transport a smartphone into to communicate with others whilst on Earth. She is also capable of creating entire dimensions.
 * Item Creation: D can create items out of nothing. She primarily used this ability to create a smartphone that allows her to communicate with others even if they are on different planets. However, she also created “game breaking”, one-time-use artifacts, like the “Hero Sword” and “Demon Lord Sword”.
 * Item Alteration In addition to creating items from nothing, D can also alter already existing ones, like how she “upgraded” Shiraori's scythe.
 * Telepathy: Following Kumoko's evolution into Shiraori, D was shown to be able to communicate with her telepathically, though this could also be due to their “connection”.
 * Stealth: Although weaker than Meido in direct combat, she is skilled at evading detection.
 * Disguise: D can hide her true appearance by making others to perceive as a vast field of darkness. However, higher-ranked gods, like Sariel, are capable of seeing through the illusion.
 * Time Manipulation: In some cases D can control world time, for example when he calls Shiraori on the phone while they are talking and stops while they are talking.
 * Resurrection: D has showcased that she can revive herself if she is killed, having shown to be capable of healing any wound inflicted and reattaching blown away body parts, causing Shiraori to theorized that she was in fact reversing time.

Other Abilities

 * Physical Abilities: It can be assumed that, like all other gods, D's physical strength is above the limit of the System. However, according to Shiraori, this is only when she is actively enhancing her body with conjuring, and without it her physical abilities are only that of an out-of-shape teenage girl.
 * Intelligence: D has displayed an almost omniscient level of intelligence, being able to perfectly predict other people's thoughts to the point where they wonder if she is reading their minds.
 * Miscellaneous Skills: D herself stated that she can do “anything” if she sets her mind to it.

Trivia

 * In the Web Novel version of the story, she owns a wide variety of powerful, although somewhat pointless, magical artifacts, some of which she lend out to Shiraori; including:
 * A cursed set of playing cards that force the loser to do whatever the winner says, which accidentally cursed Sophia into only being able to refer to Shiraori as “master”.
 * A baseball bat that can make anything it hits a “home run”, which was used to destroy the barrier that surrounded the Elf Village.
 * A watch with a pocket dimension inside it where time flows differently, which was used to seal Güliedistodiez to prevent him from attacking Wrath.
 * She has a general dislike toward dragons.
 * She is known to be an avid gamer.
 * Her voice actor voiced Visha from Youjo Senki and Fubuki from One Punch Man among others.
 * D seems to dislike women with larger chests than her, intentionally “setting” the reincarnations to be smaller than hers.
 * Sophia and Karnatia are exceptions who “might” get larger, which is precisely what happened.
 * This is also why Shiraori, who shares D's looks, is the third largest among the reincarnations.