Introduction
Demons in SMT are not necessarily your enemy. In fact, rather than just killing them all willy-nilly, you can negotiate with them or bribe them to leave you alone. You can also get them to join your cause, which is crucial to your survival. This isn't always possible, however... there are some demons who you will have to fight, and there are some demons you will only be able to get into your party by demon fusion, another important skill.
Alignment is very important when dealing with demons. Demons of an opposite alignment will see you as an enemy, and light and dark demons will frequently ignore you if you're weaker than them. Also, you cannot summon demons of an opposite alignment. There are nine possible alignments, ranging from light-law to dark-chaos.
However, demons are not just organised by alignment. They are also split up into races, each which correspond to an alignment. These demon races serve to the demons more of an identity than just their alignment, and are important for demon fusion.

Sources
Apis source
Chonchon source
Encyclopedia Mythica

Races
I have declined to give translations for the demon race names because they do not translate very well into English. However, I will give English equivalents for the kanji used in race names so far, as well as the readings of the kanji that are used...
  • 天 (ten) = heaven
  • 使 (shi) = use, messenger, envoy
  • 聖 (sei) = holy
  • 獣 (juu) = beast
  • 霊 (rei, ryou) = spirit
  • 妖 (you) = bewitching, mysterious
  • 鳥 (chou) = bird
  • 魔 (ma) = demon
  • 地 (chi) = earth
  • 精 (sei) = spirit, fairy, energy
  • 夜 (ya) = evening, night
  • 堕 (da) = fallen, degenerate
  • 凶 (kyou) = bad luck, disaster, evil
  • 邪 (ja) = evil
  • 鬼 (ki) = devil, ogre
  • 樹 (ju) = tree
  • 屍 (shi) = death
  • 悪 (aku) = evil
  • 龍 (ryuu) = dragon
  • 幽 (yuu) = ghost
  • 外 (ge) = outside, wrong
  • 道 (dou) = path
  • Welcome
          Welcome to Demondex. The aim of this site is to provide pictures and data of the various demons of the SMT universe. Data will primarily be taken from SMT if..., but later additions from games such as the Devil Summoner games will be added when possible. I will not be adding demons from the Persona games. Well, I might, but I'd have to whip up a separate Tarot Arcanum page, and I wanna concentrate on this first. As for Devil Children, I'll have to get a lot farther in the game before I have a good selection of demon data to start with.
          This page requires Japanese support. I will be using Japanese on this page. For example, I will be leaving the names of demons I could not recognise in the original katakana until an appropriate romanisation is found. It's easy to add Japanese support to most browsers, so please check the site that distributes your browser for more information. If you can't read katakana, sorry. I'll see what I can do. ^^;

    天使 (Tenshi) // Light-Law
          Archangel. LV 24, 213HP, 58MP. Can use Maha Agionn, Hama, Raku Kaja, Media and Heat Wave. Eighth of the nine orders of angels (Seraphim, Cherubim, Throne, Dominion, Virtue, Power, Principality, Archangel, and Angel) Details
          Angel. LV 14, 83HP, 37MP. Can use Zanma, Hama, Media and Penpatra. The lowest ranking angel of the nine orders. Details
          Holy Ghost. LV 9, 44HP, 23MP. Can use Bufu, Zan, Hapilma, Dia, Patra and Mapper. (No definition yet. I'm guessing it's a holy ghost, rather than The Holy Ghost.) Details

    聖獣 (Seijuu) // Light-Law
          Apis. LV 25, 377HP, 50MP. Can use Hamaon, Media, Recarmdora, Bodyslam and Heel Drop. A manisfestation of the Egyptian god Ptah in the form of a bull; enshrined in Memphis. Details

    聖霊 (Seirei) // Light-Neutral
          Undine. LV 26, 184HP, 98MP. Can use Zionga, Hapilma, Marin Karin, Diarama and Medirama. Teutonic water-spirit that likes to associate with humans. Created without a soul, but can obtain one and become human by marrying one and giving birth to a child. Details
          Flamies. LV 13, 98HP, 35MP. Can use Agi, Agilao, Maha Agi and Wall of Flames. (I think this is an Atlus Demon). Details
          Aquans. LV 12, 82HP, 38MP. Can use Maha Zio, Dia, Media, Posumdi and Wall of Water. (I think this is an Atlus Demon). Details

    妖鳥 (Youchou) // Neutral-Law
          Aello. LV 28, 205HP, 89MP. Can use Maha Bufula, Taru Kaja, Scratch and Wingbeat. A Harpy employed to punish crimes and keep peace. Was also employed to take people down to the underworld, where she tortured them. Details
          Celaeno. LV 22, 114HP, 74MP. Can use Zionga, Mudo, Rakunda, Trafuri and Scratch. "The Dark": another one of the three harpies. Lover of Zephyrus and mother of Achilles' horses Xanthus and Balius. Details
          Ocypete. LV 18, 82HP, 47MP. Can use Tarunda, Song of Happiness, Lullaby, Scratch and Wingbeat. One of the three Harpies. Details
          Benu. LV 9, 43HP, 30MP. Can use Maha Zan, Hapilma, Sukunda, Dia, Patra and Mapper. Egyptian sun bird of Heliopolis. Symbol of life, and associated with the death and rebirth of Osiris. Details

    妖魔 (Youma) // Neutral-Law
          Apsaras. LV 19, 80HP, 111MP. Can use Zanma, Maka Jama, Raku Kaja, Maka Kaja and Media. Beautiful nature spirits who danced to the music of Gandharvas. Details
          Kinnali. LV 12, 66HP, 70MP. Can use Agi, Agilao, Bufula and Hapilma. (No definition yet.) Details

    地霊 (Chirei) // Neutral-Neutral
          Dwarf. LV 18, 155HP, 40MP. Can use Zan, Hama, Raku Kaja, Tetra Kaja and Hell Fang. Small humanoids with long beards who are famous for their craftsmanship. Details
          Bucca-Boo. LV 15, 103HP, 31MP. Can use Bufu, Bufula, Maha Bufu and Sibabu. (No definition yet.) Details
          Sudama. LV 11, 81HP, 27MP. Can use Maha Zan, Maka Jama, De Kaja, Raku Kaja and Petradi. Japanese spirits that inhabit rocks. Details
          Kobold. LV 6, 47HP, 19MP. Can use Raku Kaja, Suku Kaja, Media, Patra and Paraladi. A German goblin that lives in mines. Tricksters that will help or harm humans depending on what they feel like doing. Details
          Knocker. LV 4, 32HP, 18MP. Can use Zan, Taru Kaja, Dia, Mapper, Trafuri and Happy Dance. English spirit that lives and works in mines. Friendly and helpful but at times mischievous. (However, not malevolent like Kobolds). Also known as Spriggans and Tommyknockers. Details

    魔獣 (Majuu) // Neutral-Neutral
          Kerberos. LV 43, 500HP, 109MP. Can use Recarm, Bind Voice, Fire Breath, Power Breath and Bite. (No definition yet.) Details
          Orthros. LV 26, 230HP, 50MP. Can use Panic Voice, Bite, Scratch and Flying Kick. (No definition yet.) Details
          Nekomata. LV 20, 103HP, 54MP. Can use Maha Zan, Marin Karin, Calmdi, Scratch and Flying Kick. Mythical Japanese cats that have gained special powers after living for a very long time.Details
          Cu Sith. LV 14, 88HP, 32MP. Can use Dormina, Trafuri, Happy Dance, Panic Voice and Bite. (No definition yet.) Details
          Cait Sith. LV 11, 60HP, 30MP. Can use Taru Kaja, Suku Kaja, Media, Mapper and Scratch. (No definition yet.) Details

    妖精 (Yousei) // Neutral-Neutral
          Banshee. LV 23, 128HP, 116MP. Can use Maha Bufu, Dormina, Mudo, Tarunda, Panic Voice. (No definition yet.) Details
          Elf. LV 16, 97HP, 69MP. Can use Zan, Maha Zan, Dormina and Hapilma. (No definition yet.) Details
          Jack Lantern. LV 13, 75HP, 43MP. Can use Agi, Agilao, Maha Agi, Taru Kaja and Calmdi. (No definition yet.) Details
          Jack Frost. LV 12, 80HP, 45MP. Can use Bufu, Bufula, Maha Bufu, Raku Kaja and Dia. (No definition yet.) Details
          Goblin. LV 8, 67HP, 40MP. Can use Zan, Taru Kaja, Suku Kaja and Maka Kaja. (No definition yet.) Details
          Pixie. LV 3, 32HP, 33MP. Can use Zio, Zionga, Hapilma and Dia. (No definition yet.) Details
          Willy. LV 2, 22HP, 25MP. Can use Agi, Pulinpa, Taru Kaja and Mapper. (No definition yet.) Details

    夜魔 (Yama) // Neutral-Chaos
          Lilim. LV 22, 125HP, 155MP. Can use Bufula, Diarama, Lullaby, Death Touch and Charming Bite. (No definition yet.) Details
          Nightmare. LV 19, 97HP, 138MP. Can use Zan, Zanma, Dormina and Sibabu. (No definition yet.) Details
          Empusas. LV 15, 80HP, 102MP. Can use Zio, Dormina, Dia, Mapper, Dark Breath and Scratch. (No definition yet.) Details
          Alp. LV 10, 63HP, 80MP. Can use Zionga, Dormina, Hama, Maka Kaja and Dia. (No definition yet.) Details
          キャク. LV 5, 46HP, 57MP. Can use Bufu, Zan, Hama, Maka Kaja and Trafuri. (No definition yet.) Details

    堕天使 (Datenshi) // Neutral-Chaos
          Baphomet. LV 30, 240HP, 128MP. Can use Bufudyne, Hapilma, Medirama, Sabatma, 99 Needles and suitsuki. (No definition yet.) Details

    凶鳥 (Kyouchou) // Dark-Law
          Furies. LV 17, 92HP, 57MP. Can use Maha Zio, Pulinpa, Mudo and Wingbeat. The Roman goddess of vengeance who torment evildoers. Details
          Fukei. LV 8, 66HP, 23MP. Can use Bufu, Zan, Pulinpa and Panic Voice. A cock with a human head from Chinese mythology. Details
          Chonchon. LV 5, 26HP, 12MP. Can use Zan, Maka Kaja, Penpatra and Scratch. A Chilean demon that appears in the form of a human head with large ears that serve as wings. They are invisible to most people, but people with strong magic power can see them. Details

    邪鬼 (Jaki) // Dark-Law
          Orc. LV 9, 81HP, 22MP. Can use Dia, Penpatra, Hell's Fist and Heel Drop. (No definition yet.) Details
          Gremlin. LV 5, 33HP, 21MP. Can use Zio, Taru Kaja, Suku Kaja and Maka Kaja. Mischievous spirits of tools and machinery which cause accidents and faults. Originally friendly towards humans, but became an enemy after humans took all the credit for themselves when gremlins helped them. Details

    妖獣 (Youjuu) // Dark-Neutral
          Black Widow. LV 30, 238HP, 53MP. Can use Bufu, Zanma, Diarama, Posumdi, Paralysing Needle and Constrict. (No definition yet.) Details
          Gyuuki. LV 27, 311HP, 38MP. Can use tsukumobari, Body Slap, abaremakuri and Heel Drop. (No definition yet.) Details
          Nue. LV 20, 152HP, 32MP. Can use Taru Kaja, Media, Bind Voice, Paralysing Bite and Scratch. (No definition yet.) Details
          Mandrake. LV 18, 111HP, 58MP. Can use Dormina, Tarunda, Patra, Posumdi, Paraladi and Bind Voice. A European mythical plant that screams terribly when uprooted; anyone who hears the scream is instantly driven mad. Details
          Bicorn. LV 14, 73HP, 25MP. Can use Bufu, Zanma, Taru Kaja, Penpatra, Petradi and Bodyslam. A mythical beast that grew fat on the flesh of good and faithful husbands. Details
          Garm. LV 11, 90HP, 21MP. Can use Taru Kaja, Panic Voice, Bite and Poison Bite. Ferocious Norse guardian of hell who will side with the giants on the day of Ragnarok. Details

    妖樹 (Youju) // Dark-Neutral
          ふくちゅうか. LV 7, 55HP, 19MP. Can use Poison Gas Breath, Bite, Digestive Fluids and suitsuki. (No definition yet.) Details

    屍鬼 (Shiki) // Dark-Neutral
          Corpse. LV 26, 342HP, 39MP. Can use Dark Breath, Death Touch, Paralysing Bite and suitsuki. (no definition yet.) Details
          Zombie-sensei. LV 9, 78HP, 11MP. Can use Death Touch, Paralysing Bite, Poison Scratch, Hell's Fist and Heel Drop. A Karukozaka High teacher who was turned into a zombie. Details
          Zombie-chan. LV 6, 48HP, 8MP. Can use Sexy Dance, Death Touch, Paralysing Bite and Poison Scratch. A female Karukozaka High student who was turned into a zombie. Details
          Zombie-kun. LV 4, 40HP, 7MP. Can use Death Touch, Paralysing Bite and Poison Scratch. A male Karukozaka High student who was turned into a zombie. Details
          Zombie Dog. LV 1, 10HP, 5MP. Can use Bite and Poison Bite. Your standard zombified dog. Details

    悪霊 (Akuryou) // Dark-Neutral
          Kuchisake. LV 13, 84HP, 33MP. Can use Sibabu, Paraladi, Lullaby and Death Touch. An object of terror for young Japanese schoolchildren; the "kuchisake" or "kuchisake onna" was a woman who went around with a mask around her face and asked children if they thought she was beautiful. When someone answered "yes", she would reveal that her mouth was horribly split from ear the ear. She also killed, and carried a knife. Details
          Ghost. LV 3, 28HP, 10MP. Can use Sibabu, Pulinpa and Death Touch. (no definition yet.) Details
          Poltergeist. LV 2, 15HP, 8MP. Can use Zan, Sukunda, Suku Kaja and Patra. (no definition yet.) Details

    邪龍 (Jaryuu) // Dark-Chaos
          Cockatrice. LV 24, 233HP, 45MP. Can use Poison Gas Breath, Petrifying Bite, Heel Drop and Flying Kick. (No definition yet.) Details
          ふくちゅうむし. LV 16, 81HP, 12MP. Can use Bite, Stomach Acid and suitsuki. (No definition yet.) Details

    幽鬼 (Yuuki) // Dark-Chaos
          Maneater. LV 27, 233HP, 56MP. Can use Parala Eye, Sexy Dance, Death touch, Paralysing Bite and Poison Scratch. (no definition yet.) Details
          Hannya. LV 24, 204HP, 55MP. Can use Zanma, Mudo, Bind Voice and 99 Needles. (No definition yet.) Details
          グーラー. LV 17, 130HP, 33MP. Can use Diarama, Death Touch, Bite and Paralysing Bite. (No definition yet.) Details
          Azumi. LV 16, 128HP, 46MP. Can use Zionga, Media, Wall of Water and Hell's Fist. (No definition yet.) Details
          Bogle. LV 13, 110HP, 33MP. Can use Zio, Zionga, Dia, Penpatra and Mapper. (No definition yet.) Details
          Ghoul. LV 13, 70HP, 29MP. Can use Diarama, Death Touch, Bite and Poisonous Bite. (No definition yet.) Details
          Ihika. LV 8, 89HP, 29MP. Can use Zio, Dia, Paraladi, Mow Down and Hell's Fist. (No definition yet.) Details
          Gaki. LV 4, 30HP, 6MP. Can use Death Touch, Bite and Scratch. A ravenous Japanese ghost that always feels extreme hunger. "Gaki" is also a term applied to kids meaning "brat". Details

    外道 (Gedou) // Dark Chaos
          Chris the Car. LV 16, 168HP, 43MP. Can use Poison Gas Breath, Bodyslam and Crush. Possibly based on Christine, from Stephen King's book by the same name? Details
          Jack Ripper. LV 10, 69HP, 12MP. Can use Sibabu, Sukunda, Suku Kaja, Dia and Mapper. An infamous serial killer who operated in London and was never caught. No one knows who he was. Details
          Slime. LV 8, 64HP, 8MP. Can use Crush and suitsuki. A demon that has failed to manisfest itself properly. Details