Characters in Grimoire of Zero. Contains unmarked spoilers.
Voiced by: Tsuyoshi Koyama (Japanese), Jason Douglas (English)
A beastfallen, who desires to become fully human.
- Badass Bandolier: He keeps a bunch of throwing knives inside them.
- Badass Cape: Dons a dark brown cape.
- Bare Your Midriff: His "shirt" (if you can even call it that) leaves little to the imagination.
- BFS: Wields a greatsword in combat.
- Blood Oath: Joins his right thumb with Zero's instead of committing to a Magically Binding Contract, in which he tears the paperwork apart instead of burning it (which would activate the contract).
- Big Damn Heroes:
- Rescues Albus when she is about to be burned at the stake.
- Stops Thirteen from being killed by Zero.
- Everyone Calls Him "Barkeep": When he was introducing himself to Zero, before he could reveal his name, she interrupts him and insists on simply addressing him as Mercenary.
- Curb-Stomp Battle: His duel with Holdem concluded fairly quickly, and played out in the former's favor. As he explained, while Holdem's speed might have been enough to beat humans, fighting another beastfallen is a different story.
- Dark and Troubled Past: Implied that he survived the persecution in his childhood because of his bestial appearance, after which in his youth he killed many mercenaries who threatened his parents.
- Half-Human Hybrid: Half-human, half-beast.
- Hypocritical Humor: Advises Zero that she needs to be modest with her body, yet (unintentionally) exposes his lower body to Zero. He also wears a shirt that doesn't even bother to cover his midriff.
- Knife Nut: He's pretty accurate with a throwing knife.
- Moment of Weakness: Has a moment of doubt when talking to Thirteen about Zero when he mentions she had to use beastfallen to learn magic in the first place and she'll discard him when he isn't useful. That moment of weakness allows him to place a spell on him that makes him scared enough to draw a sword on Zero.
- Mr. Fanservice: He's large and pretty well-built and as said before that shirt doesn't leave much to the imagination. He is also occasionally seen without his shirt, or stark naked.
- Nice Guy: Although he clearly wants to seem more harsh, in reality the Mercenary has a rather positive personality. In particular, he immediately tells Zero that her precious stones are worth a fortune, or he goes out at night to release the slaves, trying not to interfere with the rest. Once it is even directly noted by Albus.
- Panthera Awesome: His beast form is a white tiger.
- Pinocchio Syndrome: He helps Zero in her quest not for the sake of money, but because of her promise to make him fully human. It's going to have to wait since housing a demon makes it so that he fused with his beast-half even more and Zero is low on magic power.
- Real Men Cook: And he aspires to open his own tavern someday.
- Screw This, I'm Outta Here!: Skedaddles immediately after Zero confesses that she is a witch.
- Screw the Rules, I'm Doing What's Right!: Averted, at first, when Thirteen arrests Albus for being a Sorceror of Zero, he makes no effort to resist, not wanting to incur the wrath of a kingdom. However, when he realizes Albus is going to be burned alive for refusing to join the the State Sorcerers, he runs to her rescue. This is before Holdem joins in the rescue when he realizes Albus is Sorena's grandaughter.
- Strong Family Resemblance: He is as big and wide as his parents.
- Taken for Granite: Briefly.
- Vitriolic Best Buds: He's reluctant to admit it, but he does care about Zero and Albus's well-being.
- Willing Channeler: Briefly housing the Nameless King of Demons to aid Zero in the final episode.
- Withholding Their Name: Zero advises him to not reveal his name as witches could potentially use it to take control of him.
- Would Hit a Girl: Won't hesitate to thump Zero on the head when she says something stupid.
Voiced by: Yumiri Hanamori (Japanese), Amanda Lee (English)
A witch who is in search of the Grimoire of Zero.
- Antiquated Linguistics: Speaks in an archaic manner, using "wagahai" to refer to herself.
- Badass Longrobe: A predominantly black one, which she wears after ditching her brown, ragged robe.
- Bare Your Midriff: She wears an open coat and a midriff-baring top.
- Dishing Out Dirt: Forms a mud barrier to block a Bounty Hunter from chasing after her and the Mercenary.
- Does Not Like Shoes: Zero eschews any footwear until the Mercenary more or less makes her wear some along with a proper outfit in the third episode. Even then, it takes some convincing, with Zero outright saying that she likes walking around in bare feet.Zero: I don't really know... I like the feeling of dirt and grass under my bare feet.
- Dude Magnet: Gains the attention of many guys after her Significant Wardrobe Shift.
- Earthy Barefoot Character: Downplayed. She prefers to get her feet dirty, but she dons a pair of boots as part of her Significant Wardrobe Shift.
- Empathic Healer: Zero casts a spell on Mercenary to enforce this whenever he takes an injury, leaving her to bear the injuries instead.
- Expy: She physically resembles Shimakaze of Kantai Collection. Curiously, the illustrator of the light novels also illustrated the official art for Shimakaze.
- Fantastic Nuke: According to Zero, the spells in her book are so dangerous that knowing only a small part of them will be enough to destroy the world.
- The Gadfly: She likes to tease the Mercenary and Albus, taking advantage of their sheer simplicity.
- Going Commando: She doesn't wear any undergarments, as seen when she takes off a green dress she was trying on.
- Idiot Hair: Sports a strand. As described in Obfuscating Stupidity, however, she is anything but idiotic.
- In the Hood: When Mercenary first meets her, Zero is wearing a hooded coat that obscures her face.
- Innocent Fanservice Girl: Doesn't understand the concept of modesty.
- Magical Barefooter: Zero is this until the Mercenary coerces her into getting a proper outfit in the third episode.
- My Hero, Zero: Her name is Zero and she's the main female character of the series, in search of the Grimoire of Zero.
- Mystical White Hair: She's a witch with long silver hair.
- Obfuscating Stupidity: While her unusual upbringing and secluded early life -have- left her very naive, she is not an idiot and sometimes plays the fool in order to get others to let their guard down.
- Older Than She Looks: Implied to be older than what her physical appearance suggests.
- Significant Wardrobe Shift: Ditches her brown, ragged robe and bare feet in exchange for a predominantly black longrobe and a pair of boots and stockings after the Mercenary insists that she gets a change of clothes.
- Teen Genius: At her young age, Zero is already quite an outstanding magician and the author of one of the strongest manuscripts, since she spent all her childhood studying and research magic.
- You Are Number 6: Number zero, in this case.
- Zettai Ryouiki: She wears thigh-high socks combined with mini shorts.
Voiced by: Yo Taichi (Japanese), Chelsea McCurdy (English)
A young magician and member of the Sorcerers of Zero who encounters Zero and Mercenary during their travels. Albus joins them on their quest to find the Grimoire of Zero.
- Bokukko: Albus uses "boku", a first-person pronoun mainly used by young boys, when she talks because she's posing as a boy.
- Boyish Short Hair: She has short hair because she's deliberately trying to look like a boy so others don't suspect she's Sorena's granddaughter.
- Curtains Match the Window: Yellow eyes to go with her blond hair.
- Dirty Kid: She tells a border guard that she is the Sex Slave of the Mercenary, covertly going to the city with him.
- Gender-Blender Name: Albus is a masculine name, and Albus is revealed to be Sorena's granddaughter.
- Heroic Resolve: Chooses to be burned, rather than join the State Sorcerers and legitimize their actions. Thankfully, Mercenary and Holdem prevent that from happening.
- King Incognito: She's the grandchild of the powerful witch Sorena, who had a great influence, judging by the retrospective cadres. But now, Albus leads the life of a homeless orphan.
- Ms. Exposition: She explains to the magic ignorant Mercenary basic fundamentals about magic and explains to the former isolationist, Zero, information about the various political factions that are currently at war.
- Raised by Grandparents: Albus is the daughter of Sorena's daughter and ordinary man who died protecting each other when she was a small child. In connection with this, she was brought up by her grandmother, the memory of which she stores.
- Strong Family Resemblance: Shares the same hair and eye color as her grandmother Sorena, which is immediately used as a hint as to why she is so zealously protective of her memory.
- Sweet Polly Oliver: Albus is actually Sorena's granddaughter and disguised herself as a boy to conceal her lineage.
- Tagalong Kid: She's the younger companion who travels with the Mercenary and Zero, helping them find the Grimoire of Zero.
- Tomboyish Voice: She believably sounds like a young boy when she talks, which helps conceal her gender.
Voiced by: Masayuki Kato (Japanese), David Wald (English)
A werewolf beastfallen, and a former prince who was expelled from his family.
- Big Damn Heroes: Saves Albus from an execution at the stake.
- Graceful Loser: Is quick to concede after losing to the Mercenary in a duel.
- Heartbroken Badass: He had one-sided feelings for Sorena and lost his way after she was executed.
- Hidden Depths: He's very knowledgeable about the workings of divination magic and creating magic circles from his time working with Sorena.
- No-Holds-Barred Beatdown: Delivers one to Thirteen to get back at him for indirectly causing the death of Sorena, only to be restrained by Mercenary.
- Off with His Head!: Averted. Instead of being beheaded, he is set free by his executioner.
- Older Than He Looks: At least 50 years old, but acts like an impulsive teenager.
- Parental Substitute: Tasked with taking care of Sorena's granddaughter (aka Albus) after she was executed at the stake.
- Promotion to Opening Titles: Starts appearing with the rest of the group in episode 9.
- Starter Villain: Used to trick women into enlisting his protection services. Mercenary beats some sense into him and makes him remember his duty toward Sorena.
- Undying Loyalty: To Sorena and Albus; the revelation that Thirteen was indirectly responsible for Sorena's death doesn't bode well with him.
- Unstoppable Rage: Needless to say, Holdem is less than pleased with the fact that Thirteen was indirectly responsible for Sorena's death, and lashes out at him in a fit of rage before being restrained by Mercenary.
Voiced by: Takehito Koyasu (Japanese), Ian Sinclair (English)
An associate of Zero, and the only survivor, other than Zero, of the massacre which led to the theft of the Grimoire of Zero.
- The Atoner: After Zero states he's going against her wishes.
- Chewbacca Defense: When Albus asks how he can defend burning witches, he doesn't defend himself so much as attack the Sorcerers of Zero for teaching magic to witches, even though they did it to defend themselves from the witch hunts caused by the plague.
- Death Faked for You: Albus fakes his death so he can go into hiding, since he may be useful in the future.
- HeelFace Turn: For the last two episodes.
- I Warned You: He told Zero that her grimoire had the potential to destroy the world in the wrong hands and told her to burn it. When she didn't, it was eventually stolen and all of the other sorcerers were killed aside from them, while the kingdom is on the verge of a war. He's the one who stole it and killed all the sorcerers in the cave.
- Jerkass: In general, an unpleasant individual that treats human life like a commodity.
- Jerkass Has a Point:
- He points out the rogue witches wouldn't have been able to cause as many problems and led the kingdom to being on the verge of a war if not for the Sorcerers of Zero merely banishing them when they use magic to commit evil in the first place after teaching them.
- Even after it's revealed he's the one who taught the Sorcerers of Zero, he also points out that they're the ones who took the power to use as a weapon rather than lead people to betterment. He only taught them.
- Manipulative Bastard: Convinces Mercenary to doubt Zero just enough to where he could influence him with a spell in order to fear her and drive both of them away from each other.
- Moral Myopia: He cares only about himself and Zero. Everyone else is a tool to be used or an obstacle to be removed.
- Not Me This Time: When accused of being responsible for the incident with Sorena, he points out he had nothing to do with it. It was a witch's experiment gone wrong and when Sorena tried to fix it she was too late and burned at the stake, kickstarting the war.
- Not So Stoic: Lampshaded by Mercenary, who notes that his intelligence drops as he loses his cool, weakening the effects of his magic on Mercenary.
- Sole Survivor: Was the only survivor of the slaughter of the caves sorcerers by the man who stole the grimoire aside from Zero. More like he killed them all and only spared Zero.
- You Are Number 6: Number thirteen, in this case.