Michael

Michael is a high-ranking archangel in the Celestial Realm. He has not yet appeared in-game, but has been mentioned by other characters including Luke, who has stated that he "reports to Michael directly."

Appearance
Though Michael's appearance is not yet known, according to Satan in Lesson 43-19, Michael's appearance is the complete opposite of Lucifer's. It was also stated in this lesson that Michael "had a certain presence about him that's impossible to put into words" and "was everything humans imagine an angel to be and more". Luke also claimed in Issue 6 of the RAD Newspaper that Michael has good fashion taste, particularly with accessories.

Personality
According to Lucifer in the chat Simeon's Complaint, Michael is "too upfront about his desires", causing him to place unreasonable responsibility onto those working under him. Despite the overworking and unreasonable demands, his subordinates seem to respect him greatly and view him as a good person.

Michael has been described by both Raphael and Mammon as weird and socially inept.

Michael can behave rather childishly; in the Devilgram Raphael's Welcome, he is said to have moped dramatically over Raphael and Lucifer not bringing human food back to the Celestial Realm for him after they took a trip to the Human World.

Michael has an immense sweet tooth, and he's most often mentioned in relation to his desire for sweets. He has rather lavish and specific tastes, and is very eager to try Devildom sweets. He has no issue sparing food for others, however, having sent Simeon and Luke a package of Celestial Realm confections while they were in the Devildom in the chat Sweets From The Celestial Realm.

In Lesson 50-10, Michael was said to be interested in astronomy, having taught Luke and Mammon about Human World constellations. This was later alluded to by Lucifer, who explained in Lesson 52-7 that Michael had Raphael create a planetarium so he could view human world stars from the Celestial Realm.

In was shown in his one and currently only M|chat with Simeon that Michael is calm, yet stern when he is angry. He prefers to talk rather than use physical discipline, in contrast with Lucifer. The Devilgram A Job From Michael further exemplifies this approach, as in it he suggested that Lucifer use more gentle tactics to correct his brothers' behavior.

Story
Note: this section may include spoilers

Background
In Lesson 23-5, Barbatos mentioned that Michael is the current leader of the Celestial Realm's legion of angels as well as the guardian angel of confectioners.

When Lucifer was still an angel, the two appeared to have a friendly sibling rivalry. The two would do things to mildly annoy each other, such as Lucifer making sure to attend the opening of the first planetarium in the Celestial Realm in Lesson 52-7 because he knew Michael had wanted to visit first. They also had a habit of pushing their responsibilities onto each other, such as when Lucifer referred a lost MC to Michael and Michael made Lucifer go to a diplomatic meeting in Devildom in his place, which Lucifer griped about in Lesson 44-15. However, the two have become estranged since the fallout of the Great Celestial War.

Main Story
According to Luke in Lesson 5-12, Michael loves sweets of all kinds.

In Lesson 49, Luke commented that he often found Michael in the great hall of the Celestial Palace where portraits of Lucifer and his brothers used to hang when they were angels. He would simply stare at the empty space, lost in thought. He claims that, although he never says anything, Michael misses the demon brothers dearly and regrets both the Great Celestial War and their resulting departure from the Celestial Realm.

Relationships
Note: this section may include spoilers

Main Character
MC was supposed to meet with Michael at two points in the series, but has not yet done so. According to Luke before the first missed meeting, Michael had been greatly looking forward to meeting MC. Despite never officially meeting, it appears that Michael knows MC on some level. Raphael mentions in his character introduction video that he has heard a lot about MC from Michael.

The two may or may not have met when the Ring of Light was given to MC and MC communicated with an unknown person.

Lucifer
In Lesson 23-3, the brothers revealed that Michael had always admired and loved Lucifer. Michael and Lucifer once had a close brotherly relationship back when Lucifer was an angel. In Lesson 43-19, they were described as being "like twins", and Mammon stated that the two were very similar to each other. Towards the end of Season 3, it was revealed that Michael had collected very important mementos from Lucifer's time in the Celestial Realm. He was very quick to discover when one of these keepsakes — the Ring of Light — was stolen, implying he still keeps track of these keepsakes closely after all these years.

Mammon
In Lesson 27-19, it was revealed by Asmodeus that Michael used to teach Mammon, but didn't know how to deal with him. This led to Lucifer taking over. Before this happened, Michael attempted to teach Mammon about the constellations, though Mammon apparently didn't absorb that information, as mentioned in Lesson 50-10. In the same scene, Mammon referred to Michael as "weird", saying he "could never forget someone as weird as him."

Satan
Satan and Michael have not formally met, with Satan stating in Lesson 43-19 that his only memories of Michael are from when he was a part of Lucifer. However, he has clear enough memories to have given MC the most details about Michael. In the same lesson, he also remarks that he thinks Michael is "up to something."

Diavolo
The extent of Diavolo and Michael's relations are unknown, but it is implied they have interacted as Michael was directly involved in choosing students for the exchange program. Michael was also indicated to be frustrated with Diavolo for the secrets he kept in Season 2, using Simeon as a messenger in Lesson 31-16 Hard to express to Diavolo that, if it's discovered that his secrets could affect the Celestial Realm, he will not hesitate to intervene.

Luke
Luke reports directly to Michael, despite a massive gap between the two's ranks. This is because, though Luke is the lowest rank of angel, Michael sees a lot of potential in Luke and the power of his protective blessings, and has taken Luke under his wing. Because Michael has such strong faith in Luke, Luke has grown extremely attached to Michael, even to the point of idolizing him. He becomes extremely upset when others talk badly about Michael and always keeps Michael's interests in mind. He told MC in Lesson 5-12 that he wanted to work on his baking skills so that he could present him with a cake.

Simeon
Simeon, like Luke, also works under Michael. Simeon does not idolize Michael in the way Luke does, but seems to respect him. Michael often asks Simeon to run errands for Devildom sweets. In the midst of one such request, Simeon vents to Lucifer in the chat Simeon's Complaint. However, when Lucifer remarked that it must be a nightmare to work under Michael due to his demands, Simeon replied that he's not a bad angel.

Simeon seems to view Michael as a friend rather than just a superior. In Lesson 23-7, if MC points out that Simeon talks about Michael as though he were a regular angel, Simeon explains that this is because they have known each other for a long time.

Raphael
Raphael also works under Michael, attending his needs closely. It is stated in his character introduction video that Raphael greatly respects Michael. It is also stated there that he is the only person who truly understands Michael.

According to Belphegor in Lesson 56-1, a large part of Raphael's sour attitude that the other brothers have complained about is due to the stress of attending Michael's needs, which tend to be difficult to fulfill with very little reward.