The main character of the game, he is a high-ranking military officer, his nationality depending on the game region (i.e. in the North American version, he is a US Marine). As per Shin Megami Tensei tradition, he is player-named and is silent except for player-selected dialogue choices.
The Captain: You effectively become this for the Strike Team after Gore field promotes you before dying and Arthur signs off on it.
Dude, Where's My Respect?: Averted. Regardless of what path you choose to follow, your allies will cheer you on as you get closer to the end of the game, especially on the Neutral Path. Prior to this, you are always asked your opinion, and it almost always winds up being taken into consideration. Furthermore, the demons steadily come to regard you as the single greatest threat on the Strike Team, and outright panic when you arrive in the final area.
Evil Laugh: Implied in the Chaos route, when Jimenez comes back to the Red Sprite after you defeat Gore. "...[You]!? Did you just laugh!?"
It's Up to You: Played with; it's made clear that you're working in the field with fellow soldiers, who you occasionally encounter and talk to. Even in the penultimate floor of the final sector, you get one last chance to exchange words with your comrades. At the same time, you're the one who has a hand in all the major advancements, such as finding the materials necessary to jump from one sector to the next, wiping out a Hate Plague, retrieving Cosmic Eggs, and pulling the plug on the last bit of resistance for your alignment.
Last Name Basis: Unusually for a Megami Tensei game, you're referred to by your last name most of the time—even in menus and the battle screen, your last name is shown instead of your first. It makes sense, as you're a military officer.
First Name Basis: Your crewmates, however, tend to go by your first name outside of briefings.
Race Lift: A more subtle example. Your appearance doesn't change, but what country you're comes from depends on what region of the game you're playing (Japanese for Japanese version, American for North American version, etc.)
The Stoic: You are actually commended by your teammates for not cracking under the strain, and this results in many members of the human good guys looking up to your character as a role model.
The commanding officer of the Red Sprite, and overall leader of the Schwarzwelt Investigation Team. He is a born leader, and greatly respected by the crew.Against the wishes of the crew, he accompanies the MC on his mission to rescue Jimenez from the demon Orias, but is mortally wounded in the battle. Before dying, he places the MC in charge of the mission and begs him to stop the Schwarzwelt.
He later returns as a Ubergestalt, thanks to the energies of the Schwarzwelt. His experiences have only reinforced his faith in humanity, essentially making him the Neutral Hero of the game. If you accept and agree with his views, he tasks you with the final mission of destroying Mem Aleph, and gives you the "brilliance" to see Mem Aleph in her true form. If you reject them, or are too far from Neutral alignment, he regards you as a danger to humanity and fights you to the death.
Badass Normal: He very nearly defeats Orias singlehandly. Too bad Orias decided to play dirty.
Unexplained Recovery: However it is Mother Maia who brings him back to life. Though how she did it is unknown.
Climax Boss: In the final sector, you meet up with him and he gets ready to discuss his plans to destroy the Schwartzwelt. If you are devoutly Lawful or Chaotic, or don't answer his alignment questions in a neutral manner, he deems you too far off the deep end and fights you. Following his death, Arthur self-terminates, the Red Sprite is left in a state of disrepair, and Jimemez or Zelenin (depending on your alignment) storm the Red Sprite and work their brainwashing mojo.
Spirit Advisor: In the Neutral Path. He's much more of an antagonist in the Law and Chaos paths.
Take Up My Sword: Commander Gore puts you in charge of the mission before he dies.
A Russian scientist assigned as the First Lieutenant to the observation crew of the Elve. Her appointment was one of the first made in preparation for the Schwarzwelt operation. She is a friendly and intelligent thinker, and dedicated to the mission.After crashlanding in the Schwarzwelt, Zelenin and the rest of the Elve crew were abducted by the demon general Mitra, who used the crew as test subjects for his experiments. As a result of all she'd seen and heard while in Mitra's custody, she hates demons and refuses to work with them under any circumstances.
However, she is persuaded by Mastema that angels are different from the demons she hates, and accepts their help. As she witnesses the atrocities committed by Jack Squad, she loses faith in humanity and falls under the thrall of Mastema. She eventually accepts an offer from him to transform into an angelic being, becoming the Law Hero of Strange Journey.
Apocalypse Maiden: If the forces of Law have their way, any surviving humans judged "worthy" of living in the Lawful Earth will live forever under the thrall of Zelenin's song, which deprives all living things of their sentient will.
Fantastic Racism: Because of her ordeal in Bootes, Zelenin hates demons, refusing to work with them regardless of the circumstances and viewing them only as tools for the study of the Schwarzwelt. The irony is, however, that she happily accepts support from Mastema's angels... even though, by Megaten terminology, angels are demons like any other, just with a different alignment.
An American mercenary who once served as an army officer. He signed up for the Schwarzwelt operation for the money, and serves on the Blue Jet's strike team. Though highly skilled, he has a severe attitude problem and cares more about survival than completing the mission.He is the sole survivor of the Blue Jet after it crashlands in Antlia and is attacked by demons. He is rescued by the MC and joins the crew of the Red Sprite. Over time he grows fond of one of his demons, Bugaboo, only for them both to be captured by Jack Squad and used in their experiments to create living weapons. After they mortally wound Bugaboo, Jimenez fuses his body with Bugaboo both to save its life, and to take vengeance on Jack.
In his new half-demon form, Jimenez becomes the Chaos Hero of the game, growing to enjoy his new powers and eventually leaving to live alongside his demonic brethren.
Gratuitous Spanish: Prone to saying "Ay Dios mio!" ("Oh my God!") whenever things go wrong. Made all the funnier because, of course, he becomes the representative of the Chaos faction, which is vehemently anti-God.
Hypocrite: Was horrified when Zelenin used her powers to make Jack's squad see their sins (or alternately: brainwashed them). In the Chaos route it turns out that he's not above using the Delphinus Parasites to take over the remaining crew of the Red Sprite.
He becomes friendly with the MC, and later says that the MC is essentially the only crew member he gives a damn about. Even after you defeat him in the Law and Neutral paths, he still shows a lot of respect for you.
The Lancer: Especially if the protagonist goes the Chaos path.
Marked Change: His strange tattoos (with a vaguely religious motif), just barely visible under his Demonica, become quite noticeable once he has shed his clothes and fused with Bugaboo.
Power Born of Madness: He starts to become a believer in this after he's affected by the Delphinus Parasite—that all living creatures are meant by Nature to be constantly snarling at each other, humans included. If you side with Chaos, he'll be joyous about spreading the Parasite through the Red Sprite, as they're no longer "oppressed" by sanity.
Screw This, I'm Outta Here!: His interest in the mission decreases exponentially the moment he becomes a half-demon, until he reaches a point where he abandons it altogether and leaves, presumably to live in the Schwarzwelt alongside the demons.
The Social Darwinist: Effectively this way once he fully sides with Chaos. As he puts it in the Chaos ending, regarding the Chaos-elemental Earth, "those who are supposed to die, will die."
The virtual intelligence of the Red Sprite. After Gore's death, he becomes the main strategist of the investigation, and is a stalwart ally of the protagonist no matter what path he takes...except on the Law and Chaos paths, in which the battle between the protagonist and Gore causes so much damage that Arthur shuts down.
The Stoic: Manages to always remain calm and collected, despite the many horrors the team encounters. It comes with being a machine.
What Measure Is a Non-Human?: Both the crew of the Red Sprite and the inhabitants of the Schwarzwelt question Arthur's existence as an independent being with a soul due to, yes, being a machine (he's referred to as a "ghost cast in circuits"). The former are a lot more open-minded and consider him one of their own; the latter hold nothing but disdain for him.
For Science!: Irving and Chen are a benign version of this who are mostly Heroic Neutral. They get geeked out of their minds over all the forma they can mess with, and Irving gets borderline creepy over how obsessed he is, but the both of them also have limits in that they consider the actions of the resident Mad Scientists in the game horrifying, and unless you pick Law or Chaos, they remain loyal members of the Red Sprite Team.
Gadgeteer Genius: Irving and Chen take material that would probably perplex MacGyver himself and make all sorts of armor and death-dealing weapons out of it.
The Medic: Zoe and Maebe usually staff the Sickbay area, though Wolf occasionally fills Maebe's spot.
Only Sane Man: In the Law and Chaos paths, Dent is arguably the least affected by the brainwashing or Hate Plague of whoever you sided with; most of his personality is still intact. Justified, as several EX Missions would be Lost Forever otherwise.
Mask of Sanity: Dent sheds his off after you finish all his missions in the Law path, revealing that he's just as crazy as everyone else.
Sliding Scale of Idealism vs. Cynicism: Over time, crew morale goes downward and differences become a problem, especially in later sectors, until ultimately some of them leave to follow Jimenez or Zelenin. In the Neutral path, Gore's resurrection and reunion with the crew brings everyone to Manly Tears and gets everyone hyped up for the end of the mission, to the point where everyone is cheering you on to go beat the snot out of the Final Boss.
Those Two Guys: The areas of the Red Sprite have at least two people in the same room at any one time who are usually working together, though Blair disappears from the deck screen towards the end of the game.
A simple demon that the team encounters in Sector Bootes. Because he is a "half breed", he was tortured and experimented on by Mitra's servants just like the humans. During the final raid on Mitra's palace, the Protagonist and Jimenez encounter and rescue Bugaboo from his tormentors, and he becomes Jimenez's demon. When he and Jimenez are captured by Jack Squad, he is mortally wounded by the Squad's experiments due to his low constitution. Desperate to save him, Jimenez convinces the Protagonist to fuse them together, so that Bugaboo may "live on" through Jimenez.
Hybrid Monster: This is the reason Mitra's minions were experimenting on him. The other half of his DNA? Human. Why this is never quite gets explained, though it's implied Mitra and his followers created him for experimental purposes.
I Owe You My Life: The reason Bugaboo is intensely loyal to Jimenez. During the investigation of Sector D, he gets to repay the favor, but he never strays from Jimenez' care.
Pokémon Speak: Although he does learn to speak broken English over time.
The British leader of a mercenary squad called, appropriately enough, Jack's Squad. He claims to have come to the Schwarzwelt in order to make a profit, but a lot of the crew suspects that he has an ulterior motive. They're right. In reality, he seeks to turn the demons of the Schwarzwelt into living weapons, and conducts horrific experiments on them to this end. After capturing Jimenez and openly stating his intention to experiment on him as well, the Protagonist leads an assault on Jack's base and defeats him in combat. He is then killed by the newly demon-fused Jimenez.
Affably Evil: Even before he tries to kill you, he admits dismay that you couldn't be friends.
Humans Are Bastards: If you ever thought only the Demons would go as far as doing experiments on their victims, Jack will prove you wrong.
Karmic Death: Jimenez became half demon thanks to Jack's own technology, so he was essentially defeated by his own experiments.
Subverted. The only reason the fusion succeeded was because you plugged your Demonica into it to power the fusion. Jack's squad was using a VERY flawed method of demon fusion and while it did produce results, there was a reason why the only demons you see under their control are mostly abominations like Ghouls, Legions, Slimes and Pisacas.
A member of Jack Squad, and Captain Jack's second in command. After Jack's death, he insists that he'll go straight, but it turns out this is a ruse. He takes command of the remnants of Jack Squad, and plans to use Jack's technology to create a "Demon Army" to use for his own purposes. Before he can do this, however, Zelenin, recently reborn an Angel, uses her brainwashing "hymm" to pacify him. He is then either killed in the Chaos path, or never seen again in the Law and Neutral paths.
Well-Intentioned Extremist: Their methods are intimidating, to say the least, but it's strongly implied that if they are sided with humanity will never have to deal with another Schwartzwelt. Louisa Ferre is the exact same on the Chaos side.
An Angel with pitch black wings that serves the Three Wise Men. The Wise Men have tasked him with finding a human capable of creating a "Kingdom of Heaven" on Earth, and seems to have his eye on Zelenin for this very purpose. However, he may have his own plans for Zelenin...
Ambition Is Evil: His goal is for the Lord to bless him with a form superior to Angels.
Villainous Breakdown: In the Neutral path, he calmly accepts his plan's failure, warns the protagonist that he hasn't seen the last of him, and leaves without conflict. In the Chaos route, however, he completely loses it and tries to kill the protagonist himself.
The demon leader of Sector Antlia. Wants to lead a demon army out of the Schwartzwelt to eradicate mankind.
Wake-Up Call Boss: Let's see, he has Light of Order, a One-Hit Kill to one of your demons in a game where putting a dead demon back in action takes 2 turns (one to revive, another to re-summon) unless you have a particular rare item or late-game spell that cuts that down to one turn, as well as Mabufudyne, a third-degree all-targeting ice spell, when you're lucky to have Bufula and Mabufu at this point.
The demon leader of Sector Carina. Wants to eat everything in the human world.
Bad Boss: He eats his minions during his boss fight.
Playing with Fire: Knows Maragidyne and his unique Black Flame spell. Asherah replaces Maragidyne with the weaker Maragion spell.
Power Born of Madness: What the Delphinus Parasite is supposed to "bless" the world with. He genuinely considers any kind of restraint on growing strength as an abomination to nature. And since raging insanity means endless culling of those who don't have perfect strength, agility, or wits, sanity has to go.
Social Darwinist: He considers Law to do nothing but succor the weak...who are meant to die quickly. All loving the weak does is inflict decay upon the strong...and so, weaken and defile the world entire. Yes, you read that correctly—he essentially considers sympathy and kindness to be evil.
The Mother Goddess in charge of Sector Grus. Once she traveled through the dreams of man and made those dreams a reality. But now that man's dreams are only filled with greed, rot, and destruction she sees no other option except the complete annihilation of humanity.
The entity at the center of the Schwarzwelt; a Mother Goddess and the leader of the forces of Chaos in this game. According to Gore, she once mothered human spirits, but has since decided to turn on them.
Knight Templar: Her ultimate reason for instigating the Schwartzwelt (in this and all prior occurrences) is that she has judged civilization to be too harmful for Mother Earth, and beyond redemption or forgiveness.
Light Is Not Good: The only Light aligned demon amongst the mothers. More specifically, Neutral-Light. But that's only her "Mother" form; her true "Empty" form is Neutral-Neutral.
Meaningful Name: As discussed in Theme Naming, her initials continue the theme of using the ma root in her name, meaning "mother". Beyond that, the Phoenician word mem (itself derived from ma) means "water," the element considered the origin of life. Furthermore, the word aleph represents the first letter of the Hebrew alphabet, and it has come to mean "the first," the numer 1, and "the origin," and it is the letter with which the name of God begins. In set theory, the term aleph is used to denote the cardinality (size) of countable and uncountable infinite sets. As if that weren't enough, the Hebrew letters Mem and Aleph represent the left and central columns of the Sefirotic Tree, associated with the female Binah and the neutral Kether, respectively, and they represent the topmost horizontal paths between sefirot (from Binah to Chokmah, and from Geburah to Chesed.) These two paths surround Da'at, the hidden node in the Tree which represents the perfect unity of the ten sefirot. Whew!
In Jewish Mysticism Mem and Aleph are two of the three mothers of creation and represent two of three primordial elements.
One-Hit Kill: MA. Basically Mitra's Light of Order, but it can also target the protagonist. And heal her, although that doesn't matter much when it turns the battle into a Luck-Based Mission. He Light and Dark element attacks are also 100% instant kills.
Power Born of Madness: She seems to be a believer in this being sacred, as she tacitly approves of Jimenez spreading the Delphinus Parasite through the Red Sprite. Given that Jimenez had spoken of freeing them from the "oppression" of sanity, the result of her self-suffusion of the world in the Chaos ending as Jimenez tells it, and the Wise Men referring to her "Empty" state as her true form during the Law climax, it's entirely possible that she's a psychic manifestation of aggregate life's will to power...unalloyed. No forethought, no calm, certainly no mercy...just willfulness and fury.
Super Empowering: Mem Aleph's breath can empower mortals as seen in the chaos route.
Taking You with Me: After you've vanquished her initial form and reduced her to her true "Empty" form, she's nothing but "naked power," incapable of creating a new world from the Schwartzwelt...but more than capable of annihilating you before succumbing to her fate.