Ultimate Despair

Ultimate Despair (超高校級の「絶望」chō kōkō kyū no "zetsubō") or Junko Enoshima's servants is an organization in the Danganronpa Series founded by Junko Enoshima.

Contribution in Spreading Despair
Ultimate Despair is described as a group of people who have "become despair". As Junko describes despair as a sort of contagion/state of mind, it can be inferred that the members of Ultimate Despair are those who have been "infected" by despair, and is in fact seen as an extension of Junko's thoughts and will. Their goal is to spread despair across the entire world, driving it into a state of self-destructive anarchy.

They started The Tragedy and kept it ongoing even after their leader's death.

They defied understanding and did various things for the sake of despair and Junko Enoshima: some starved themselves till their bodies were husks, some offered up their parents to Junko to use for experiments on murder, others slaughtered innocent civilians and forced them to kill themselves as a tribute to their dead leader, one removed their own eye and replaced it with Junko's, possibly to see her despair.

It is also said some members of Ultimate Despair attempted to produce children with Junko's corpse. It is notable that although many other members might have done similar things, Nagito Komaeda is the only person whose act was fully established; he took Junko's left hand and sewed it onto himself, resulting in him having a non-functioning left hand. Another interesting fact is the majority of the people who became Ultimate Despair have their eyes turn gray spirals, red or crimson. However, this could only be a symbolism of their affiliation to despair. In Izuru Kamukura's case, his red eyes were a side effect from the project that he had taken part in.

The Brainwashing of Class 77-B
In Danganronpa 3, it is revealed that most of the members were actually brainwashed by Junko using Ryota Mitarai's brainwashing techniques and combining it with the recording of the first mutual killing game and notes on human psychology she stole from Yasuke Matsuda. However, in the case of Class 77-B, Junko combined Ryota's brainwashing techniques with a live feed of their class representative's execution instead.

It's also revealed that after their brainwashing, members of Ultimate Despair still retain their personalities. However, their minds were conditioned to desire despair, similarly to Junko. Because of this, they commit various terrible acts. Upon their "graduation", Class 77-B announced their plans for the world as though they were positive and humanitarian - Describing their plans as though they were bringing happiness or leading the world on the right path. However, both Nekomaru and Nagito described themselves and their classmates as Ultimate Despair. It's likely that due to now thinking like their leader, Junko Enoshima, they considered the spread of despair and horror as a positive and benevolent act, hence their words.

The only ones that weren't brainwashed were Izuru, who joined out of boredom/curiosity and isn't shown to be invested in despair, and Mukuro Ikusaba, who only joined Ultimate Despair out of love for her sister. Monaca Towa was also an unofficial member of Ultimate Despair, idolizing Junko and trying to be her sucessor until she realized just how insane Nagito was about Hope and Despair, frightening her into giving up trying to follow her footsteps. The only person who might joined of his free will is Ted Chikatilo as it is never explicitly stated he was brainwashed.

As Remnants of Despair
After their leader died in The Ultimate Punishment, most members of Ultimate Despair followed her example and committed suicide. The ones who survived became known as the Remnants of Despair (絶望の残党 zetsubō no zantō).

Eventually, the Future Foundation secured the custody of fifteen of them - at first only aware that they were survivors from Hope's Peak Academy. When Makoto Naegi, by that time a member of the 14th Division of the Future Foundation, realized that the survivors were in fact, Remnants of Despair, he quickly directed them to Jabberwock Island in secret. Makoto made them enter the Neo World Program, where their memories were reset to a time prior to their entering Hope's Peak Academy, before they were manipulated by Junko - resulting in most of them not recognizing each other. The plan was to overwrite their memories of themselves as Ultimate Despair, replacing them with good ones in order to undo all the damage Junko had done to them.

Unfortunately, this plan ended in failure, due to Junko's interference as a virus AI was uploaded by Izuru Kamukura right before they were put into the program. As a result, they ended up experiencing the same violent event that befell the Class of 78, albeit in a realistically-simulated environment. This came to be known as the Killing School Trip. By the end of the incident, ten of the original fifteen ended up temporarily comatose.

The ending of the Danganronpa 2: Goodbye Despair heavily implied that even though the Neo World Program did not erase any memories, the remnants of Ultimate Despair who had made it out of the Neo World Program have kept their memories from inside the Neo World Program, and were assumed to have recanted their beliefs in the concept of despair itself, thus leading them to abandon their status as Ultimate Despair. The surviving Remnants of Despair currently reside on Jabberwock Island and are attempting to find a way to awaken their comatose friends, while the Future Foundation left them alone and continued cleaning up the world and putting an end to The Tragedy. At the very least it did undo all of Junko's brainwashing which allowed them to regain control and Izuru's original self as Hajime.

After the events of Danganronpa 2, the Remnants of Despair still active in the world are few and in disarray for both their decrease in number and their loss of prominent members, like Junko and Izuru. They are described as on the verge of extinction by Monokuma. However, they still continued with their terrorist activities, managing to carry out forty attacks in only a month. The last of Ultimate Despair is vanquished when the members see the Hope brainwashing video created by Ryota Mitarai.

On Jabberwock Island, Hinata, encountering a large fleet of warships, is shown to still have red eyes due to side effects of the Forced Shutdown that didn't erase his memories as Izuru. Hajime and his friends are rescued by Byakuya Togami's forces, and Hajime is later seen in the Future Foundation Headquarters after presumably defeating a number of soldiers.

The last of Ultimate Despair appears to be vanquished when the members see the Hope brainwashing video created by Ryota Mitarai. Nonetheless, in order to preserve Future Foundation's credibility and power to rebuild the world, the main 15 Remnants of Despair decided to take the blame for the Final Killing Game before returning back to Jabberwock Island.

Member Relationships
In general, while the organization was active, many of its members have professed their love for Junko, but there are extreme variations of their professions of love. One prominent example of this is when Mikan Tsumiki, who had contracted Despair Disease within the Neo World Program, ended up remembering who she really was before being sent into the Neo World Program, and then proceeded to kill Ibuki Mioda and the unfortunate Hiyoko Saionji; when she was finally identified as the blackened, she proceeded to profess her love for Junko in a way that nobody was able to understand at all. The contrast to that would be Nagito, whose machinations in Towa City to "devote himself to despair" stems from hatred towards despair, ironic considering that he was a member of Ultimate Despair. His motive is revealed that, just like his motive for trying to start Monokuma's Mutual Killing Game in Danganronpa 2, he wanted create a great despair in order to give birth to a great hope.

Of note is that Ultimate Despair was divided in ranks (mentioned by Mukuro Ikusaba in Danganronpa IF).

Their relationships with Junko never seemed to extend beyond idolatry. The Remnants of Despair became that purely because Junko had died, and the act of sewing her body parts onto themselves forcibly is evidence of idolization. Junko has never professed any kind of love for any of the members of Ultimate Despair, save for her own sister Mukuro, but this was because she would, instead, induce "despair" in them in the name of love.

What is very clear, however, is that while members are mostly disparate, separated units who may choose to act alone (which they often do, as evidenced in the uprising in Towa City), their main goal was always to spread despair.

Most of Class 77-B still seemed to maintain some sort of comradery even after falling into despair. Peko continued to loyally serve Fuyuhiko as an Ultimate Despair, and during a battle with some of the leaders of Future Foundation, Nekomaru and Akane aided Peko. Ibuki and Hiyoko hosted a concert and used their talents to spread despair. Mahiru snapped photographs as Sonia used her talent to rally a brainwashed army.

The only one who never established any known relationship with other Ultimate Despairs (except Junko and Mukuro) is Izuru. Despite being made into a well known figurehead of the Ultimate Despair, in actuality Izuru merely observes the battle between Hope and Despairs. Furthermore, upon his request, Junko had erased any memories the Class 77-B has of Izuru, while he himself also erased his own memory of Class 77, so that he would not be bored when he meet the Remnants of Despair again. It's unknown if they worked together during the Tragedy.

Trivia

 * The Japanese word 残党 zantō used as "remnants" in the Japanese name of the "Remnants of Despair" is actually a more specific term meaning "remnants of a defeated faction/political party". This alludes to the fact that Ultimate Despair was an organization, and that the survivors of the Neo World Program defeated Junko.
 * Monaca is the only unofficial member of the Ultimate Despair. She has shown several similarities to the official Ultimate Despair members from their obsession with Junko and despair to their mission to spread despair. They also display the same amount of insanity when it comes to spreading despair or displaying love for Junko. Although she gave up following her footsteps after realizing one of the followers is insane.
 * The reason why Class 77-B's true nature was not revealed initially is due to them having faked their death, and thus taken off the list of protected students. Their memories of Izuru Kamukura/Hajime Hinata were also removed by Junko upon his request and vice versa, as he believed it will be boring if they knew each other.
 * Even though Izuru is labeled as a member of Ultimate Despair, in reality, he was just affiliated with the organization. After Chiaki Nanami's death, he would leave Ultimate Despair and observe the battle between Hope and Despair to see for himself which side fits him better. His motivation is very similar to Nagito Komaeda's: both chose to join Ultimate Despair to witness the battle between hope and despair, however Izuru joined out of free will, while Nagito was brainwashed to do so.