Leviathan

"Nothing beats 2D! The hardcore otaku third-born."

"'Mr. Dark and Moody, full-time otaku and shut-in. His goldfish Henry is his (only) friend.'"

Leviathan is the Avatar of Envy and is the 3rd oldest among the seven demon brothers. He is one of the main characters in Obey Me! One Master to Rule Them All that is involved in the intimacy system of the game; therefore, users can interact and raise their relationship with him.

Appearance
Leviathan has purple-colored hair with side-swept bangs that slopes to his left, eyes that are orange with a blue gradient, and very pale skin. Like all of the demon brothers, Leviathan paints his nails; sometimes the nail polish is cyan and sometimes it's a dark indigo.

Personality
Leviathan is an otaku and hikikomori. He spends almost all of his free time playing video games, watching anime, or in some way consuming media, and he peppers his speech with netspeak (and sometimes Yoda speech). He tends to rant about whatever he's interested in, especially The Tale of the Seven Lords, and makes frequent references to anime/manga/books. He's also a gigantic social recluse and rarely leaves his room, choosing to take online classes instead of having to go to school and often has high anxiety when he's forced to attend social gatherings.

He does not think very highly of himself, often calling himself a worthless otaku, and assumes others do not think highly of him as well. In lesson 40, it is revealed that he was a General in the Celestial Realm’s army, and that ever since they were at peace with the Devildom, he’d felt like a useless freeloader who had no purpose if he wasn’t fighting a war. This could explain why he threw himself so wholeheartedly into fictional worlds, in order to have something else to be passionate about.

As the Avatar of Envy, Leviathan can be easily turned to jealousy and self-pity. He often remarks about how situations are "unfair" and how "lucky" others are. Though he has a superiority complex when it comes to his interests, when this superiority is threatened in some major way, he lashes out in jealousy. This is demonstrated during Lesson  4-1 when he flies into a rage -- changing into his Demon form -- over the thought of the MC being a bigger TSL fan than he is.

Leviathan is also a tsundere. He's easily embarrassed despite a cold, reserved exterior, and though he calls the MC a "normie", he gradually opens up to them once they form a pact.

Main Story Normal
Just as Mammon's showing MC the House of Lamentation, Leviathan angrily appears before Mammon and demands his money back. Mammon uses MC as a distraction and makes a quick escape, leaving MC behind. Leviathan quickly forms an idea to use the human exchange student to his advantage. He then drags MC to his room with caution so that no one would see a “normie” coming to his room.

The conversation goes on until they reach the topic on The Tale of the Seven Lords (TSL). MC doesn't know anything about TSL, so Leviathan gives a very detailed summary of it. Moving on to the real point on why he invited MC to his room, Leviathan suggests that MC should make a pact with Mammon in order to get his money back from his older brother. This way, Mammon would have no choice but to obey. In order to form the pact, Leviathan claims that MC must have something that Mammon would do anything to get: the credit card that Lucifer took away from him.

After getting a hint from Lucifer on the credit card's whereabouts, the two head to the kitchen and retrieve the card from the freezer. When Mammon makes a surprise entrance in the kitchen and sees that the two have his credit card, he pleads for them to give it back. Leviathan sets a condition that he must first make a pact with MC. After scaring Mammon using Lucifer's name, he relents and officially makes a pact with MC.

To gain access to the stairs that lead up to the attic, MC decides to distract Lucifer with the help of Leviathan's TSL vinyl soundtrack. But to get the soundtrack, MC has to convince Leviathan to give it to them. After failing to enter his room with his secret code phrase, MC decides to make a competition between them and Leviathan to decide who is the biggest TSL fan.

Leviathan is upset with the idea that MC thinks that they know more about his favorite series, so he accepts the challenge. At the competition, MC receives the easiest questions and Leviathan the hardest. However, Leviathan is able to answer all of the questions correctly with ease. Depending on who MC went to, they reveal their trump card which sends Leviathan flying into a rage. He turns into this demon form and attacks MC. Lucifer is able to stop Leviathan from hurting MC and orders him to go to his room to cool down, leaving the TSL contest as a draw.

Later, MC receives a phone call from Leviathan to go and meet him in the planetarium. Leviathan claims that MC had won the contest to see who the bigger TSL fan is and agrees to enter into a pact with them. After sealing the contract, Leviathan asks what MC's ulterior motive is in wanting a pact from him, so they ask Leviathan to borrow them his copy of the TSL soundtrack. He agrees to it, but he's upset about the fact that MC only wanted to make a pact with him for this reason.

In lesson 7, the demon brothers and all the exchange students are invited on a retreat to the Demon Lord's Castle. Once there, Leviathan is roomed together with Beelzebub and Luke. During the castle tour, a talking painting interrupts. It turns out to be an ex-girlfriend of Asmodeus. After a fight between them, she pulls Leviathan, Beelzebub, Mammon, Solomon and MC into the painting.

The painting operated as a kind of teleportation device, as everyone pulled inside lands in an underground labyrinth where Leviathan's old pet snake, Henry 1.0 lives. The snake doesn't recognize Leviathan and tries to attack the group, prompting them to run away. They try to find a hiding spot until they can figure out a way to get out of the labyrinth. Beelzebub wants to eat Henry 1.0 but Leviathan insists that nobody will hurt his old pet. Solomon decides to use his power to make Asmodeus strong enough to tame Henry 1.0. Once Henry 1.0 is fully enchanted by Asmodeus, he helps them find the labyrinth's exit.

Later on, Leviathan, MC, Mammon, and Beelzebub try to sneak into Lucifer's room to get a picture of him sleeping so that Asmodeus will enter into a pact with MC. Instead, they encounter Cerberus and in their attempt to escape end up back in the labyrinth and pursued once more by Henry 1.0. MC (temporarily using Solomon's power), summons Asmodeus and amplifies his powers to charm Henry 1.0 again and safely leave the labyrinth. This leads to Lucifer lecturing them, but Asmodeus cuts it off by entering in the pact with MC.

When Lucifer and Satan switch bodies, Leviathan, Mammon and MC come up with the idea to make the two play a real life simulator game, hoping it would help them reconcile. Leviathan registers himself as "Leviachan" and Mammon as "StupidMammon". He then explains to the others what they have to do in order to win the game. He made MC the heroine, meaning everyone has to compete to get MC's acceptance of a love confession.

Leviathan proudly announces that he will win this game. He feeds MC his homemade bento box, which is Ruri-chan themed and includes a Japanese omelet and some fried shrimp. On the final day, the game turns into a monster survival game. After defeating all the monsters, the final boss spawns on the rooftop, which turns out to be Cerberus. Seeing how Cerberus is threatening his brothers' lives, Lucifer successfully tames him and the game ends.

Lessons missing here...

At Diavolo's birthday party (which doubled as a welcome party for MC), Leviathan gives MC the "most popular item from Akuzon" as a gift.

Lucifer tells his brothers that MC will have to leave the Devildom soon and to spend their time with them before they leave.

Leviathan was enraged after asking Mammon to give him back his money again. Mammon runs away with MC and if MC chooses to hide in Leviathan's room, they will hide in his bathtub. Leviathan will enter the room, badmouthing Mammon, then complain that Mammon took MC with him and that wasn't fair. He then asks Henry what he thinks about all of this, telling him that the thought of MC leaving makes him sad. He then says that "my MC" is leaving before switching back to getting his money back from Mammon. He leaves the room and MC and Mammon are finally able to escape outside.

It isn't long before Leviathan catches up and Mammon ends up leaving MC to deal with him. Leviathan confesses that he doesn't want MC to leave, and that he doesn't want to lose them. At this point, MC can either hug or kiss Leviathan. Kissing him results in Leviathan stuttering and then asking MC if it was an accident and if they lost their balance and stumbled into him lips-first. He couldn't believe that someone would kiss a "yucky otaku" like him by choice. If MC hugs him, he'll become flustered and ask MC to marry him. After one of the options plays out, Leviathan runs after Mammon.

Right before MC leaves the Devildom, Leviathan tells them that he will keep the save data for the game they were working on beating together. He continues on to tell MC that he couldn't tell them how happy he was when they said that he was their true friend. He finishes his turn with that MC is special to him, "really special, in a way that no one else is."

Trivia

 * His symbolic animal is a serpent, which symbolizes fertility, life, and healing.
 * Levi is the only character (apart from MC) who does not use his own photo as his profile picture.
 * He notes in a text message that he is the Grand Admiral of The Hell's Navy.
 * In lesson 40, it is revealed that he is a general and once commanded an army of angels to fight against the demons.
 * Levi enjoys bufo egg-milk tea (Milk tea with boba).
 * Levi's dream is to become a programmer, as he told MC in the chat titled Future Dream. His "more realistic dream" is to become a gaming Deviltuber (Youtuber) and live stream daily.
 * Levi enjoys drawing but does not consider himself skilled.
 * Levi is a cosplayer.
 * Levi can sew. He learned this skill by making cosplays and is first revealed in the Summer Festival event.
 * His sewing ability is called upon once more when Simeon asks him to sew all the costumes for the event Henry and the Seven Lords.
 * Asmodeus also asks Levi to sew ten outfits that he'd designed himself for his fashion show in lesson 32-6.
 * His name on Devilgram is "L3V1".
 * "Zaramela" is one of his top 3 Idols. He made his brothers worry when he used the map app to go after a clue on where they lived, a story that revealed itself through several chats including EMERGENCY!(6).
 * His name comes from the sea serpent from the Bible
 * in the modern Hebrew language his name (לִוְיָתָן) means "whale"
 * This relates to his bedroom decorations of ornamental jellyfish and gigantic aquariums, as well as his bathtub bed
 * He has a pet goldfish named "Henry" in honor of the TSL character of the same name.
 * He also had a former pet snake that escaped named "Henry" and calls it "Henry 1.0".
 * In the TSL fandom, the Lord of Shadow is based on him
 * The Lord of Shadow is also his favorite character next to Henry.
 * Levi can summon Lotan and often uses his ability as a threat.
 * In Lesson 9-2 he says that he owns 36 Ruri-chan figurines.
 * In the Dark Santa event, Leviathan bought a bunch of presents for himself.
 * One of the things that he specifically bought was a Ruri-chan figure with a skirt that he was hoping to receive in the gift exchange.
 * His worst subject is seductive speechcraft; this also happens to be a class he isn't able to take online.
 * According to Solomon, Leviathan has gone through 2 goldfish both by the name of Henry.
 * It is said that Lucifer is the reason Leviathan is into Anime.
 * Levi’s phone has a devil horn case with scaled pattern and face.

From Devilgram stories

 * Levi is shown to have defined abs, yet he's also very out of shape.
 * He can't jump rope and run one lap around the House of Lamentation in his Devilgram Love, Friendship, and Justice.
 * In the devilgram Strongest of Them All, after being picked on by Asmodeus and Satan for his flabby body, he tries to show his strength by attempting to pick up and throw Beelzebub, but instead injures his back.
 * In Beel's Boot Camp, he asks Beel to help him get into shape since Lucifer threatened to degrade him to a lower demon for his physical weakness.
 * From Satan's Be You Devilgram, Levi says that he's terrified by non-otakus.
 * In the Devilgram Levi the Maestro, it is revealed that he learned to play multiple musical instruments.