In terms of overall combat he is a lot stronger than his fellow classmates. This is extremely evident when fighting Amaimon — while he easily curbstomped his allies, he had to put a little more effort defeating him.
Made even more obvious when Rin fought Amaimon with his sword drawn, almost defeating the latter if the battle wasn't interrupted. Amaimon, one of the strongest demons in Gehenna that no exorcist will be able to defeat on their own.
Expanded upon and taken Up to Eleven in episode 17, where he utterly trashes Amaimon, who was earlier shown to be casually defeating Shura and Angel - a high class exorcist and the strongest exorcist in the order, respectively.
Dissing Shiro or making Rin recall his Heroic Sacrifice isn't a good idea either...
When he's first introduced, he's beating up a gang of delinquents for torturing a flock of pigeons. His immediate move from casual to violent suggests that "hurting animals" might be another Berserk Button of his.
Berserk Mode: If he stays in his demonic state too long, he'll become more or less a vessel of violence and not much else. However, this is suggested to be a sign of how inexperienced and scared he is in regard to his demonic heritage.
Betty and Veronica: The Archie for Shiemi's Betty and Izumo's Veronica and the Veronica to Yukio's Betty for Shiemi's Archie.
Big Brother Instinct: As a child, he was very protective of Yukio and would chase off people that would bully him. As they got older, Rin stopped looking after Yukio as much since he can now take care of himself, but Rin is still very protective of his younger brother.
"I would never hurt my younger brother!"
The Big Guy: Since he is the strongest of the group with little else to offer Konekomaru recommends that he acts as a backup version of this.
Book Dumb: Especially when compared to Yukio, since while Yukio is a Teen Genius Rin is a former junior high school drop out.
Brutal Honesty: At times, since he hasn't had much experience interacting with others due to negative past experiences.
Bully Hunter: Heavily implied as the audience first sees him beating up a bunch of guys for killing/torturing pigeons, he always used to protect Yukio and even have a few flashbacks that show he mostly got into fights this way. Arguably influenced his decision to become an Exorcist; hostile demons can count as really big bullies since they target humans.
Character Development: Already in practice. He started out much angrier and discontented than he is now. Although still insecure, he seems to be happier and a bit more easygoing. Though it is possible at least some of this is faked.
Complete Immortality: Implied. He's got the Healing Factor down pat, and the lack of aging can be inferred from a demons unnaturally long lifespan, which would imply slow physical development, and the human host seems to stop aging after being possessed by a demon, which in Rin's case would be which he first awakened his demon powers.
Cool Sword: His sword acts as both his Demon Heart and was a prized possession of Suguro's temple beforehand.
Death Glare: Has one strong enough to make lesser demons back off. If he's doing this and his eyes have suddenly changed to be blue with red pupils, that's your cue to get out of there before he decides to break out his Blue Flames.
Does Not Know His Own Strength: A weird example since he's more nonchalant about his Super Strength. In the first episode where he was doing things to get hired, he showed an impressive display of strength, only to cause damage at the expense of his current boss. On the other hand, the rest of the time he seems to be okay; seems to be brought on more by nervousness (like him breaking the sink) than anything since he can manage well enough otherwise.
Also worth noting that the incidents where he has trouble with his strength only show up in the Anime. He never shows any trouble with this strength (aside from casually using it) in the Manga.
Dude, Where's My Respect?: Rescues a young girl from a tower of falling cans while on the job in the first episode... only to reveal he got fired for it. At least the girl's father thanked him for saving her.
Fangs Are Evil: When Rin is pissed, has drawn Kurikara and has gone out ofcontrol, his fangs become more pronounced and look much more deadly. Not helped by his tendency to growl and howl in this state.
Heroic BSOD: Occurs in chapters 25 and 26 of the manga, where he thinks he's better off dead, can't unsheathe his sword due to lack of confidence, and is sentenced to execution. After a Cool Down Hug from Shiemi, he recovers, but his confidence issues are still present and prevent him from drawing his sword for quite a while, and it's obvious that he's been suffering from a very well-hidden form of Survivors Guilt since Fujimoto's death.
Heal It With Fire: Rin, when defeating the Impure King, chants a mantra to purify the surrounding area. With the Power of Friendship and True Companions in his heart, he ensured the flames would only destroy the infection and not harm the other people fighting.
Laser-Guided Tykebomb: Is kept alive just to become a weapon to destroy Satan. Inverted since the ones who were raising him were good guys, and most of them had the good sense to be nice to him about it.
Locked Out of the Loop: Pre-series he was the only one in his family to not be an exorcist, and managed to grow up semi-normal. There are hints that there are other things that both he and Yukio don't know about their heritage and Satan.
In addition, the Greek word for phosphorus, Φωσφόρος , literally means "light-bearer." In Latin, this is "lucem ferre," more commonly shortened to Lucifer. And this is also the name of the eldest son of Satan.
Stealth Hi/Bye: Of all people, Rin manages to pull this off in the Kyoto arc, disappearing from besides Shura and suddenly appearing nearby Tatsuma. Not even Shura knows how he did it.
Stepford Smiler: Has shows signs of being a low level version of this... Alternatively, it could be that he's actually a very high version, as it took many chapters to get even a hint things weren't as they seemed. And what is wrong? He has serious Survivor Guilt, questions why he was saved and at times thinks he shouldn't exist. Not to mention constantly belittles himself and is flat out terrified of being alone.
Super-Powered Evil Side: Subverted — he can somewhat control his flames, but the longer he stays with his sword drawn, the more he loses control of himself. As shown in Chapter 14, he can completely stop acting like a human.
Super Strength: The one power he's always had even before awakening. It caused...problems...at times. Mostly because, true to form, he tends to use it without thinking.
Supreme Chef: It is said to be his "best feature". Word of God is that he never messes up and though he doesn't have anything truly fancy in his repritor, he gets it perfectlyevery single time.
Team Chef: Also counts at this, especially during the camping trip.
Telepathy: He and Kuro are able to communicate using telepathy by reading Kuro's mind. He's also able to "hear" the thoughts of other demons, since he used sound to find the ghost-child in an amusement park but no one else could hear it, and some demons seem to respond to his thoughts as well, though that might also be a result of sensing his "killing intent" towards them for attacking his friends (like when the Leaper attacked Bon after the teacher left or when Godaiin was being harassed in school). In the anime, this extends to Ukobach and a boar demon as well.
Survivor Guilt: Rin has flat out issues due to Shiro sacrificing himself to save him; early on he says that the reason he chose to be a exorcist was to not have to be in that position again.
Tiger Versus Dragon: A textbook tiger to Suguro's dragon. Rin is lazy, impulsive, tries to solve everything on his own, and usually with brute force alone,(though this is possibly justified by the fact he didn't have any friends until recently) while Suguro is rather smart, hardworking, and loves cleaning and meditation, not to mention he's an eloquent reciter, and team work means a lot to him.
To Be a Master: Rin desires to be like Shiro and become the highest class Exorcist. While not his only goal, it is a major one.
Beware the Nice Ones: Not matter how nice he may seem he is still a very effective exorcist. Not to mention, like his brother, he does have a temper and has enough demonic blood to make him really scary when he gets mad.
Big Little Brother: Sort of. He's extremely smart (got the top score in his incoming class), tall, very handsome and a well accomplished Middle First Class Exorcist at 15 years old. Compare him to his older, shorter, less brilliant twin, Rin, who's only an ExWire currently.
Broken Ace: There isn't anything he can't do, but he has a great level of self-hatred for his own weaknesses and on some level hating his brother and the only father he ever knew.
Cain and Abel: Playing with a Trope. He looks like the good son of the pair, being a polite exorcist and all, but he came within a hair's width of shooting his brother in the third episode/second chapter. Then they settle into more of a Vitrolic Best Buds relationship which is their default relationship apparently. But there are hints that Yukio, what with his status as The Corruptible, might go to the bad...
The Comically Serious: At times, due to his tendency to be as serious as possible yet at the same he does like gag manga. Best pictured here (at the bottom panel.)
Deadpan Snarker: Has shown shades of this in the manga and the Japanese version of this anime. It's more prominent in the English dub, courtesy of Alex von David's script and Johnny Yong Bosch's performance.
A girl who had a demon affecting (crippling) her legs, who loves gardening and all nature. Good-natured and sweet. Demonstrates extensive knowledge of plants. Used to be seen only in a kimono and still has a tendency to wear them. The Love Interest for both Yukio and Rin.
Adorkable: As a result of being very cute and awkward around people.
Badass Adorable: Not only is Shiemi a very cute a sweet girl with an equally adorable companion, but they are also the most effective tamer/demon team of the group and the most versatile members period being able to cover healing, defense and offense equally well.
Barrier Warrior: In fighting the Naberius during the Page exam, she used Niichan to grow a tree barrier.
Combat Medic: Her purpose of the group with her plant-based powerset.
Comically Missing the Point/Insult Backfire: When Izumo laments that she can't believe she has friends like her, who's "as shameless as a weed", she thinks it's a pep talk and vows to become "as strong as a weed".
Foil: To Izumo since while both are tamers she is friendly and humble, as oppossed to Izumo's abrasive and proud personality. Even their character designs and hair/eye colors are opposite of each other.
Flower in Her Hair: After she grows her hair out of its bob she uses flower based hairclips to keep her bangs out of her face. Considering that Nii-chan spends most of his time hiding in her hair they might count as being a sentient "flower in her hair" as well.
Fragile Flower: Probably the most sensitive person in this manga, but she's getting more assertive.
Innocent Flower Girl: Sorta subverted since she's not sick anymore and she's starting to get over her shyness, but she's still kind and she still has plenty of knowledge on plants, flowers and the like. And she also lives at a herbs/plant shop.
Oblivious to Love: She doesn't seem to notice all the love triangles that involve her. Justified by the fact she was born very sickly and so didn't go outside much. And then her legs got possessed by a demon, extending the time.
Plucky Girl: She strives to be as determined as a weed and won't let anything bring her spirits for too long.
Tiger Versus Dragon: A textbook dragon to Rin's tiger. Suguro is rather smart, hardworking, and loves cleaning and meditation, not to mention he's an eloquent reciter, and team work means a lot to him, while Rin is lazy, impulsive, tries to solve everything on his own, and usually with brute force alone.
A stubborn, haughty girl with twintails who initially mocked Shiemi. Instant Expert at calling up Familiars, rather skilled in combat.
Abusive Parents: Chapter 52 gives us a glimpse into Izumo's past and introduces us to her mother; a woman who originally loved her children but came to blame Izumo for all her problems, leading to her Demonic Possession, and even her trying to kill her own children.
Break the Haughty: In her first episode, almost leading to her familiars turning against her.
Cry Cute: Can't help herself but weep in shame in Chapter 5/Episode 7, at the end of a double-whammy, when she realized that not only has Paku never thought of her as anything more than just a good childhood friend, but even did a shoddy job protecting her from an attacking ghoul.
Foil: To Shiemi since while both are tamers she is outgoing and assertive, as oppossed to Shiemi's shy and passive personality. Even their character designs and hair/eye colors are opposite of each other.
Friendless Background: Happened due to being the only one who could see demons. Possibly also due to her fear of being captured by the Illuminati.
Jerk with a Heart of Gold: While rather rude and blunt to those around her, she's also a genuinely good girl. She encouraged Shiemi (in her own way) when the latter has given up and is the first to defend Rin (and for a while, the only one to stand by his side) when it's revealed that he's the son of Satan and all his other friends are uneasy around him.
Butt Monkey: Is definitely one, to his own family no less. His father's and older brother's reaction when he finally comes home? Punt him on the head for dying his hair pink. Even his mother sends him a death threat instead of coming to see him off. He's appropriately horrified. This turns out to be a Deconstruction what with his ties to the Illuminati and his Stepford Smiler status recently being revealed.
He summons a high level Wisdom King class demon that has been his Familiar since childhood, showing he has the abilities of a high-ranking Tamer.
Later he uses the same flame-based techniques that his older brother — a high ranking Exorcist with a Knight and Aria Meister — uses.
Was able to stop an unleashed Rin in his tracks and even force him back (though this could have been because Rin was too shocked to retaliate).
In Chapter 55 he battles against Izumo's fox familiars and utterly annihilates both within seconds, presumably killing them permanently.
Dangerously Genre Savvy: Shima demonstrates he is this in Chapter 56 when he suggests to Lucifer that the Illuminati guards have a better chance of defeating Rin, because he would most likely hesitate to kill humans, pointing out that love is fragile and is both his strength and his weakness.
Desperately Looking for a Purpose in Life: He has no goals and chose the Aria class only because Bon and Konekomaru chose to become Arias as well. According to them the Knight class suits him better, and Konekomaru calls him out on not being motivated enough to choose so. It looks like he found it in working for the Illuminati.
Dissonant Serenity: Since his Face-Heel Turn in Chapter 48, he's maintained his easygoing, laidback attitude, but with that same tone he flat out tells Izumo that he hates everything, and is very comfortable with telling Lucifer that Rin's weakness is his capacity to love humans. He also seems okay with sending Izumo to her Fate Worse than Death, and before that, apologizes to his friends and says goodbye to them as if he didn't just kidnap Izumo and casually counter Rin's attacks. But see Stepford Smiler below for why.
Nun Too Holy: Despite being raised in a temple and training to be a monk and exorcist it doesn't seen to stop him from trying to flirt with almost every girl he meets, especially around Izumo. Lampshaded by Konekomaru...
Playing with Fire: He can summon a creature which uses black flames to burn demons and human souls.
Power Strain Blackout: He can summon Yamantaka, but he knocks out immediately afterwards for hours at a time.
Rose-Haired Sweetie: To match his outgoing, positive, flirty and friendly persona, much to his father's chagrin...
Dye Hard: ...as it wasn't originally pink. Which may be foreshadowing the fact that his "sweetie" traits are just as fake as the rose hair is.
Shaping Your Attacks: He has used his black flames to form a spear tip, a buzzsaw-like wave and even paper-thin spikes of fire that erupt from the ground.
Simple Staff: His weapon of choice, leading Konekomaru to think he would make a good knight meister. He does.
Stepford Smiler: Reveals that despite his happy, cheery demeanor, he actually hates everything, except, the ladies. This results in some major Dissonant Serenity since he's working for the Illuminati and doesn't really seem to care...unless you pay attention to his eyes.
Theme Naming: His older siblings are named Kinzou (not that one) and Juuzou (not that one, either). Later on we find out his father Yaozou and his late eldest brother Takezou fall under this as well. The middle sibling is also named Gozo, and it fully seems to be something all the guys in his family get.
The Unfavorite: We meet his family during the Myou Dha arc - his mother threatens him instead of saying goodbye and his brothers treat Bon and Konekomaru better than how they treat him.
One of the cram school students. He doesn't talk, instead uses a Bunny Rabbit puppet to communicate rudely to the others.
Deep Sleep: Since his puppet said "Nemu go back to sleep" immediately after Takaraopened his eyes during the fight with Shima that may mean that he has been sleeping through every cram class, conversation, and event he has been present for so far.
Don't Wake the Sleeper: At least his hand puppet seems to think so, since even briefly waking up caused it to tell Takara to go back to sleep.
Hand Puppet: His Pink Rabbit he uses to talk. Then again, it seems the human is the puppet and the rabbit is the ventriloquist.
Eyes Always Shut: Adding to his unusual and mysterious appearance. Justified since he doesn't need to see since he is asleep while his demon possessed puppet controls him.
Expy: Let's see: A rather short blond haired boy who is actually an upper-classman of sorts when compared to the rest of cast, has a pink rabbit plush he carries around, has a surprisingly vicious temper despite his appearance, and has... issues with being woken up. Are we talking about Nemu or Honey-sempai?
Jerkass: When he does talk he is very rude. Or at least his demon is.
Last Name Basis: No one ever uses his first name since they don't know him well enough.
Marionette Master: An unusual variety of Tamer, able to summon and control dolls. At least, that's what the demon controlling him claims he is.
Meaningful Name: The name Nemu can mean "Sleep" and if his puppet is to be believed then in every scene of him so far Takara has been asleep, possibly so his demon can control him better.
Red Herring: Incredibly suspicious kid older than the other cram students and possible more powerful than he should be? Gotta be The Mole... except he isn't. Though that doesn't mean he's in the clear, as now the audience must wonder what a "Coordinator" means here.
Sleepwalking: In a matter of speaking, since his demon has been controlling Takara's body while he's asleep.
The Quiet One: He rarely speaks but when he does it is only through his puppet.
Chairman of the True Cross Academy who, after Fujimoto died, was ordered to kill Rin. However, he accepted Rin's proposal in becoming an Exorcist and entered him into True Cross Academy. Can turn into a dog.
Adaptation Dye-Job: Of eye color variety. He has blue eyes in the manga and green eyes in the anime.
Anti Anti Christ: He's a demon, one of Satan's kin, who's convinced that "peace is the disorder in which people can coexist", loves the human world, and only wants to protect it in a way any sane human can consider reasonable.
Authority Equals Asskicking/Royals Who Actually Do Something: He's 2nd highest ranking of all demon in terms of strength and one of the Eight Demon Kings. He's right below his father in terms of strength in the Gehenna Hierarchy. He is also an Honorary Knight which, in exorcist rankings, is two ranks below Paladin. It's possible he'd be higher too, were it not for his heritage.
Beware the Nice Ones/Beware the Silly Ones: He's actually pretty friendly and personable most of the time. Even if he comes off as creepy, he rarely ever says a harsh word to anyone and is always very polite. Furthermore, he's an Otaku who loves to dress in hilariously flamboyant fashions while also going on Large Ham speeches about various things and making a spectacle of himself. His room is filled with plushies and fandom merchandise. He's the second most powerful demon in the Gehenna hierarchy - second only to Satan. And he is also Samael, master of time and space, able to restrain Amaimon and Rin at the same time if he has to, without breaking a sweat. His rage has only come close to being triggered once and it was by Shura, who tried to interrogate him. She immediately knew to back off.
Bunny-Ears Lawyer: Very Camp and a large ham but a high ranking exorcist, dean of a prestigious school the size of a city, and one of the strongest demon kings of Gehenna.
Camp Straight: Definitely camp (especially in the anime) and most likely straight as he's commented in the manga that he shares Rin's preference for women of the "devilish" type. He also has some Ship Tease with Shura in the manga.
Eccentric Mentor: If Mephisto really is on the side of the Exorcists, then he is this. Older than most of other characters? Check. Knows more than he lets on most of the time? Check. Usually acts like comic relief? Check. Eccentric? Double check. Cares not for what others may think? Considering his fashion sense, probably check. Acts like a mentor/protector/guide? Check, to his students and school. More powerful than he shows? Considering he was able to drag a berserker Rin around while calmly sheathing his sword and pleasantly talking to someone, that would most likely be a checknote He hasn't been in a legitimate fight yet, though, so it's yet to be confirmed. Seems to prefer letting his students solve problems by themselves? Mostly check, with him making a few nudges here and there. He seems to fit this trope very well but then, if he's not on the side he claims to be on, he may be a subversion.
Familiar: Has two different ones so far. One is Ukobach, a demon who, as shown in the anime, cooks food for Rin and Yukio. The other is apparently disguised as his umbrella◊ most of the time.
For the Lulz: His reason for being the leader of the side that wants to take down his dad is because he's bored. And because humans are entertaining.
Gratuitous German: While it is the correct usage, he gratuitously uses "eins, zwei, drei" occasionally, which simply means "one, two, three". He has also used two spells called "Kuchen Cuckoo House" (kuchen being the German word for "cake", used in other languages to describe various other sweets) and "Das Stärkste Gefängnis", meaning "the Strongest Prison". This is possibly justified in that his namesake originates from German folklore.
Hellish Pupils: To make him seem untrustworthy and show that he's a demon.
Nice Hat: A distinctive top hat he keeps when he turns into a bug.
Otaku: According to the character profiles in the tankobon, he enjoys movies, manga, anime, video games, music, toys, and subcultures. He admits it in chapter 39, and seems to be outright proud of it.
Public Domain Character: In the anime continuity, at least, where it's made explicit that he is the very same Mephistopheles who contracted with Faust in the original folktale. In the manga, this remains to be seen.
Really 700 Years Old: Has been working with the exorcists for 200 years and is older than Amaimon who is over 1000 years old.
Reality Warper: Amongst others, he was shown to be able to transform into a dog, pull a clock out of his hat (in which he was able to hide/entrap Amaimon), transport Rin's and his own conscious to Gehenna, and he also made the Exorcist shop inaccessable by physical means. As it turned out, he's the King of Time and Space.
Time Stands Still: One of his powers he can use. It is seen used to stop the slowly expanding artificially created Gehenna Gate. Unfortunately this will last four to five months at best.
Sharp-Dressed Man: When he isn't wearing his silliest outfit (the one with the tights and the puffy pants,) he's this and has worn both a simple white suit and a striped, but still snazzy, one. It seems to depend on his mood and the occasion.
Space Master: As the Demon King of Time and Space, he has this ability. It only came up a few times so far, like when he trapped Ammaimon in his hat, or when he transported Rin's and his own soul to Gehenna.
26-year-old Upper First Class Exorcist swordsman. Prefers wearing clothing that does little to hide her incredibly curvy figure. Has long red hair and acts a bit childish. Also an instructor.
Action Girl: The only female that actually fights instead of relying on her familiars.
Badass: An Upper First-Class exorcist trained personally by Father Fujimoto. She basically kicks ass every time she draws her sword. Even Mephisto takes her seriously when she starts to (perhaps unknowingly) mess with his plans a little. For Mephisto, this is definitely saying something as he doesn't seem to take things seriously 98% of the time.
Boobs of Steel: In addition to being an effective fighter she also has the largest chest of the female cast.
Book Dumb: While nowhere near as much as Rin, she does show some shades of this, shown when neither her nor Rin could read a cursive written letter.
Brilliant, but Lazy: She avoided promotions to be near Fujimoto, who she also considered as her father; however she really is that lazy and that gifted, which infuriates Yukio to no end.
Christmas Cake: She introduces herself to her class as eighteen and constantly interrupts Yukio whenever he tries to tell everyone that she's really twenty-seven years old.
Creepy Cool Crosses: Although not exactly creepy, it is seen that his sword has a cross emblazoned on the blade.
Curb-Stomp Battle: Both on the delivering and receiving ends. He easily manages to subdue both Rin and Shura, but when Amaimon went into an Unstoppable Rage, he was almost immediately knocked out.
This man is a tool in every sense of the word, but he is undeniably Bad Ass. He One-Hit KO the Impure Princess, a similar demon just under the Impure King in the decay family of demons, which took Rin merging with a higher-tier demon and about 200 other exorcists to beat. He's the Paladin for a reason.
Fantastic Racism: In the anime, "for the kin of Satan, just being alive is a sin!" In the manga, referring to Mephisto, "his kind specializes in deceit!"
Green-Eyed Monster: In chapter 38 of the manga, we see just how upset he was that he didn't get the chance to fight the Impure King, and sees how Rin was the one to defeat it as adding insult to injury.
Honor Before Reason: As of episode 24, he's admitted to realizing that the Vatican is going in the wrong direction, but he refuses to betray them and will still follow his orders.
Idiot Hero: Whether or not he truly counts as a "Hero" may vary, but he is the Paladin...and even admits to being dimwitted.
Jerk Ass: Arrogant, takes great pleasure in antagonizing the other characters (Rin in particular), has plenty of Kick the Dog moments, and frequently refers to the memory of his predecessor (who was both a better paladin and overall person) with open contempt.
Kick the Dog: In the anime, he takes exceptional pleasure in trying to kill Neuhause's wife despite Shiemi begging him to show her mercy
Lawful Stupid: Arthur will follow the orders of his superiors, without question, even knowing that they may obstruct some people's good intentions. He does get a bit better in the anime where he saves Shura and Shiemi in episode 25. He also leaves without incident after the final battle.
The Paladin: After Fujimoto's death he was given the title of highest ranking exorcist of the Order.
Cool Old Guy: No matter how badly he's treated or how his temple is insulted he just smiles and stays calm to try and keep Bon from being discouraged.
Crouching Moron, Hidden Badass: That odd, slightly perverted and almost wimpy guy over there? He is the head priest of the Myōō Dharani and if you give him a reason, he will show you that he definitely earned it.
Innocently Insensitive: A bonus chapter focusing on a Christmas with the Kyoto Trio that takes place pre-joining up with True Cross, has him constantly forget about Renzo, calling Bon and Koneko is "precious little brothers" but makes no mention of Renzo. Renzo lampshades this but Kinzo doesn't notice.
The eldest sibling of the three Hojo daughters and a Middle First-Class exorcist at the Kyoto Branch.
Jerkass: How he treated Rin on their first meeting, while possessing Fujimoto.
Jerk with a Heart of Gold: However, the Anime plays with it, stating because no one can house his flames, he can't stay in Assiah and has little understanding of life. When he fell in love with Yuri, and she was sentenced to death, he caused the Blue Night in an attempt to save her. Then again, they didn't make an attempt to gloss over all the deaths he's caused.
Superpower Meltdown: While destroying hosts is a relatively common problem with powerful demons, which is why they use various PowerLimiters to stay in Assiah, as the strongest demon of all his mere presence causes this these leading to a lot of gore and Body Horror for his unfortunate victims.
Thinking Up Portals: Is the only being who can naturally, and efficiently, create a Gehenna Gate. However, there is rarely a person who can last long enough for him to create one.
Authority Equals Asskicking: He's only 7th or 8th highest ranking of all demons in terms of strength, making him one of the weakest of the demon kings, but see Badass below.
Badass: He's a special kind. "I murdered so many of his brethren, so he'll cooperate". He also fights Berserk!Rin pretty well while carrying Shiemi on one shoulder. He has a reputation of being impossible for any exorcist to beat.
Berserk Button: A good way to get him serious or into a fight is to laugh at him. So don't laugh at him. Ever.
Beware the Silly Ones: He may be odd but he can break a man's arm by poking it and kill any exorcist who tries to stop him.
Meaningful Name: He shares a name with a Biblical Prince of Hell, which is only to be expected.
Morphic Resonance: His hamster form is mostly green with a lighter colored hair-horn that mimics his human form.
I Shall Taunt You: Or in this case "I will pretend to play a Japanese version of tag to get you to fight me" or "I will target your Love Interest and pretend to marry her (or chew her lips off) to make you take fighting me more seriously".
Immortality Begins at Twenty: While his human host appears to be a teenager, the 10th volume of the manga mentions Amaimon has been using him for almost a thousand years.
Psychopathic Manchild: He treats fighting like its a game to him, wants to kill anyone that he finds annoying, and doesn't care many people up hurt or killed because of his actions long as he doesn't upset his big brother.
A cat sith who used to be the guardian deity of some local silk farmers. Was forgotten by people as the times changed, going berserk, but Fujimoto was able to tame him and make him his familiar. Later became Rin's familiar after he calmed Kuro from the rage of hearing about Fujimoto's death.
Dark Lord on Life Support: Though only seen in the shadows in the beginning, it is heavily assumed that, during his preparation for his Big Entrance, he's shown to have been connected to a heart monitor and IV drip. When we do see all of him it's clear his condition is much worse than what was implied before.
Ill Boy: That said, he's still in bad shape and spends a lot of his speech pausing to cough. Now the fans have to wonder what can make a demon that ill... Judging by what he tells his scientists about making a "perfect body for his father" he might just be suffering a weaker version of Satan's tendency of destroying his hosts, like what Amaimon displayed before by releasing his Demon Heart.
Knight Templar: Genuinely believes that mixing the worlds of Gehenna and Assiah will solve the world's ills. Mephisto disagrees, believing that the desire to overcome one's bad situation makes humanity unique.
Light 'em Up: When he makes his entrance and subsequently destroys the barriers of True Cross Order branches around the world.
Meaningful Name: Lucifer means "Light-Bearer", as mentioned above under Rin.
Super Power Meltdown: He pushed his human host just a bit too much with his big entrance and it caused him to cough up some blood. Even showing up in Assiah to talk for a short period of time causes his human body to brake down like his father does, despite still being hooked up to everything meant to keep him stable.
Tears of Blood: Shortly after showing his human face for a brief time to speak with his subordinates he started suffering from these (along with a Psychic Nosebleed) to show how fragile his body really is.
Affably Evil: He is always very polite, even when he betrays both the exorcists and Mamushi. In fact, he arguably became even more polite after he revealed himself to be evil.
Batman Gambit: Pulls one off by obtaining both demon eyes through a bit of manipulation and trickery, then using them to deliberately awaken the Impure King. He knew that this would cause Tatsuma to show up and try to defeat the Impure King using his familiar Kurara. This weakened Tatsuma, allowing Toudou to kill him (who was saved by a revived Karura) and allow him to eat Karura to gain his power. It had all gone according to plan.
First one: after revealing himself as an exorcist fallen to a demon, he mentioned he was always in the shadow of his father and brothers, and he never could voice his doubts about his path. It rattles Yukio, but Yukio decides that he is not Saburota, but himself.
Second one: In their next confrontation, Saburota says that Yukio's father and brother are what have defined his paths in life and that he had no real choice in his path, leading him to despise his brother for having no idea what agony he went through. Yukio admits that he does love and hate his brother, but above all else he hates himself the most.
Obfuscating Stupidity: He was first seen as an Upper Second Class exorcist with a timid personality who provided some exposition about an incident involving one of the demon eyes. He seemed like an incompetent, but reasonably brave and decent, guy. And then it turns out it was all an act. He had in fact already turned traitor and only exposed himelf as The Mole in the chapter in which he was introduced. He has since shown considerable competence and cunning. He is now one to watch out for.
Start of Darkness: He described his. He wanted to be like his father and brother, but was discontent with living a life he felt was shaped by others. Ultimately he became a demon and is working for his own goals.
The Corrupter: He convinced a loyal member of the Kyoto Branch Office to give him the dangerous Right Eye of the Impure King. He convinced Renzou to betray his family and join the Illuminati. He is actively attempting to manipulate Yukio for unknown but definitely unsavory ends.
Little is known about them as a whole but so far only one of them has had their identity revealed.
The Mole: Their main purpose for the order is to infiltrate and keep tabs on the Order of the True Cross, so far there are two in the Vatican itself and one in the Japanese branch. For tropes specific to the Japan Branch mole see Renzou Shima in the Cram School Student's section.
Gonk: He has a very squat design which suits him perfectly since it makes him look like a very fatchild instead of a normal adult, he is even shorter than Izumo's mother when he is standing next to them as they is sitting in their wheelchair.
Grandfather to Rin and Yukio. First seen during the Blue Night in episode one and having lost his daughter, Rin and Yukio's mother to a witch hunt, he has good reasons for his prejudice against all things demon, as well as some ill will towards members of the True Cross Order.
Lower-second class exorcist who gave birth to Rin and Yukio. She was known as the "Witch of the Forest" and was ordered to be burned at the stake, resulting in the Blue Night. While she may end up becoming a Canon Foreigner of sorts when the manga reveals more about Rin and Yukio's mother so far this character has only been established in the anime's continuity.
Time Lord: Kinda, since officially he is considered to be "kin of Saemel, King of Time" he can be considered one of these. His ability to "eat" memories is apparently based on erasing the event from a person's personal history, or changing past events so the person doesn't remember them happening so his connection to "Time" isn't that strange.