A Kitsune from Japan and the daughter of the Yokai leader, who stumbles into San Francisco after being attacked by the Conspiracy of Serpents.
- Angel Unaware: Kasumi doesn't know she's Amaterasu until the very end.
- Badass Adorable: Kasumi is damn cute, even shy, but determined, a skilled fighter, and she's also a goddess.
- Birds of a Feather: She and Grete have tons in common and bond quickly over that matter.
- Fantastic Foxes: As a Kitsune, she's a magic foxlike being.
- Game Face: Besides being able to transform into a giant fox, when she fights in human form, her skin goes white with red marks, her eyes go gold, and she gains a set of sharp teeth.
- God in Human Form: Kasumi is actually the incarnation of Amaterasu, with a natural human form, even if she's a Kitsune.
- Interspecies Romance: She's a Kitsune, and falls for a werewolf.
- Master of Illusion: She's very talented with making illusions, enough to even fool Yamada and Kukulcan at differing points.
- Ship Tease: She and Grete get a bunch together, with Kasumi clearly in awe of her. By the battle of Japan, Kasumi confesses that Grete has her heart.
Susanoo No Mikoto
The Japanese God of Storms, son of Izanagi and Izanami, and the slayer of the Yamata no Orochi. Susanoo is a skilled warrior and hero in his own right, seeking to protect the world from the Conspiracy of Serpents.
- Archenemy: His arch-foe is the Yamata no Orochi, or Yamada. The two despise one another and have an enmity going back centuries.
- The Atoner: Susanoo was once a wild, cruel god who even tormented his sister Amaterasu. He feels horrible for it and has devoted himself to being a hero to make up for it.
- Big Brother Instinct: He's devoted to protected Kasumi and as she's Amaterasu, she's actually his beloved sister's soul in a new body.
- Big Damn Heroes: He's introduced saving Hardestadt from Apophis.
- Birds of a Feather: He and Hardestadt bond instantly over their tendency to wander the earth, have adventures and save people.
- God in Human Form: He's a god, and takes the form of a tall, handsome man with stormy grey eyes.
- Hero of Another Story: Susanoo has a number of heroic adventures himself in the past where he's saved countless people. Long ago, he even dispatched the Yamata no Orochi, or so he thought.
- Master Swordsman: Susanoo wields the Kusanagi blade and is an exceptional warrior with it.
- Nice Guy: In contrast to the admitted dick he could be in the past, Susanoo is very pleasant and relaxed.
- Old Shame: He's a bit embarrassed by how he defeated the Yamata no Orochi in the past by getting it drunk first.
- Surprisingly Sudden Death: Susanoo engages Yamada who promptly dispatches him by ripping out his heart.
- Walking the Earth: He travels the world, saving people as well.
A werewolf from the Germanic forests who was an old friend of Hardestadt's. Thorunn is the one who brought the werewolf clans into a nation, and plays a major role in Under the Cold Moon.
- Action Girl: A total and complete badass who could hang with the best of them.
- Action Mom: As much a warrior as ever, even when her daughter was a baby.
- Archenemy: Nobody hated Siegfried more than her, and the two were bitter rivals for nearly two thousand years.
- Authority Equals Asskicking: Thorunn is the queen of the werewolf clans, and one of the singular most capable and badass werewolves in the entire series.
- Cain and Abel: The "Abel" to Siegfried's "Cain." She's hardly the only of Siegfried's siblings who opposes him, but she lasts the longest and she comes the closest to putting down her horrendous brother.
- Cannot Spit It Out: A variant. She freely admitted her love for Hardestadt as a friend and lover, but she had a hard time telling him she had a daughter and he was the father.
- Dark and Troubled Past: Siegfried ensured she didn't have a pretty time growing up, murdering her family members one by one and subjecting her to horrific psychological abuse she likens to rape in a fashion.
- Died Standing Up: During her death in battle, she dies on her feet, "a warrior to the last."
- Dying Moment of Awesome: She fought to her last breath against her brother, killing every single wolf he brought with him and coming within a near literal inch of finishing Siegfried.
- Heroic Sacrifice: By far one of the most poignant and awesome in the entire series. Thorunn gives her life utterly slaughtering Siegfried's forces for the sake of those she's protecting and almost takes out Siegfried himself, expiring of her wounds an inch before she can touch him.
- Failed a Spot Check: She didn't realize Siegfried placed a silver dagger in the place where he engaged her. In the honor-bound werewolf culture, she likely didn't even consider he'd go that far.
- Interspecies Romance: She had an off-again, on-again romance with Hardestadt over the many centuries they knew one another.
- Lady of War: Elegant, strong, caring and a great warrior.
- Like Mother, Like Daughter: There's little wonder as to where Grete got half of her own skills as a Jaeger from (the other half, of course, being from Hardestadt).
- Mixed Ancestry: Her mother was a German werewolf. Her father was a Roman soldier from Numidia named Corvus.
- Posthumous Character: Her presence is restricted to flashbacks when it's revealed she's not actually Grete Ravenhollow, but in fact her mother, and she's revealed to have died centuries before the main plot at the hands of Siegfried's forces.
- Pre-Mortem One-Liner: She has one hell of a one before she goes out swinging against Siegfried's forces:Thorunn: "Look closely, craven! Brand this into your eyes, all of you! See the way a warrior dies!
- Reasonable Authority Figure: She's a beloved and capable leader during her tenure as queen of the clans, and one who's willing to protect them with every drop of energy and life in her body. Literally.
- Red Baron: "The Queen of the Clans."
- Royals Who Actually Do Something: She was considered a queen to the werewolf nation, and a front-lines fighter.
- So Proud of You: She cameos at the end of Conspiracy of Serpents to see her daughter from Valhalla and wordlessly gives her a warrior salute, smiling with pride and love.
An old-flame of Hardestadt Delac's in 1925. She finds herself on the run from a sinister cult of Cthulhu worshippers and comes to Hardestadt for help.
- Anti Anti Christ: Cthulhu wants to use his daughter to arrive on earth and herald the apocalypse. Maggie tells him in no uncertain terms to get lost.
- Apocalypse Maiden: Turns out Maggie is really Cthylla, daughter of Cthulhu, and her father plans on using her as a gateway to arrive on earth, triggering the apocalypse. Maggie manages to overcome his influence in the end, but she realizes it's only a temporary thing, so she leaves earth and goes into a magical sleep forever to prevent him from ever winning.
- But Now I Must Go: Rather than risk Cthulhu using her as a portal to earth, Maggie leaves earth forever.
- Cute Monster Girl: Despite being the daughter of old squid-face, Maggie's beautiful even as a red-skinned humanoid with wings.
- Daddy's Girl: Maggie loves her adopted father, Albert Harrington. Not so much her birth father, Cthulhu.
- Did Not Get the Girl: She and Hardestadt don't end up together, with Maggie willingly going into a magical sleep forever to prevent her father from eventually using her to cause the apocalypse.
- Did You Just Flip Off Cthulhu?: When her father—the actual Cthulhu—tries to use her to materialize on earth—Maggie seals him off, telling him to "get lost."
- Did You Just Romance Cthulhu?: It turns out that Maggie is really Cthylla, the daughter of Cthulhu and unwilling Apocalypse Maiden. She also has a romance with Hardestadt. Also, her mother did this literally, resulting in Maggie's existence.
- The Flapper: Probably inevitable given she's from 1925.
- Half-Human Hybrid: Half human and half Great Old One.
- Happily Adopted: Maggie was adopted by Albert Harrington and she clearly loves him a great deal.
- Heroic Willpower: You have to have some impressive willpower to overcome the influence of a Great Old One!
- Humans Are Special: Having lived a a human informs hers actions and helps her to bond with Micheal Seer.
- New Old Flame: She's a former girlfriend of Hardestadt who shows up in need of help in 1925. They rekindle their romance, but, as a Foregone Conclusion, they don't remain together.
- Odd Friendship: Becomes friends with Micheal Seer who's taken the power of an eldritch god.
- Walking Spoiler: You can see how much is whited out. By the end of the story it's revealed: not only is Albert Harrington not her father, but Thomas Nero is also not her father, just a Red Herring. Her birth father is Cthulhu and he plans on using her to arrive on earth to trigger the apocalypse, which forces her to seal herself away forever to save the earth.
- You Remind Me of X: Nero tells her that Maggie reminds him of his deceased daughter, Hannah, with him thinking Hannah would be like her if she was still alive.
A former mermaid who made a pact for legs and mortality to claim the man she loved. Later married Hardestadt, then known as Diarmuid ua Duibhne.
- Deal with the Devil: She made a bargain with the Sea Witch. Twice. Her second bargain, to spare her and Diarmuid? Was to offer his everlasting sorrow from her eventual death for the Sea Witch.
- Cute Mute: Part of her pact was her voice being removed, forever. She gets by on a sign language she and Hardestadt invented.
- Famous Last Words: The last she has the strength to sign:"Rivers ever return to the great ocean. I will always be with you, Diarmuid. I will ever be with you. You are my sea, my love. I would not trade this for anything. My love for you is as boundless, as eternal, as deep as the greatest ocean. My song, my sea, my love."
- Second Love: Her love for the Prince named Conn turned out to be painful and carried an unknown betrayal from him. She eventually formed a deeper bond with Hardestadt, or Diarmuid then.
- Your Days Are Numbered: Her pact meant she had twenty years to live, something she accepted and eventually embraced.
A Mudang living in 11th century Goryeo and Hardestadt, or Sung-yeol's then wife.
- Action Girl: Sun-hyo is not just a skilled shaman, she's a talented fighter as well.
- All-Loving Hero: Sun-hyo is a kind woman who responds to suffering spirits with infinite compassion.
- Deadpan Snarker: Her response to her husband's concern? Tease him a lot about being overprotective with dry humor.
- Scars Are Forever: Sun-hyo is heavily scarred from her Kumiho enemy savaging her as a little girl.
- You Killed My Father: Sun-hyo's nemesis is a Kumiho, a fox demon, who ate and wore her father as a disguise to try to eat her alive.
A professor, a medium and an ally of Stadt who joins him in his investigation of Castle Krolock.
- Badass Normal: While his abilities as a medium grant him some minor supernatural abilities, they're pretty useless in a straight up fight. This makes him—for all intents and purposes—a normal human who's badass enough to fight vampires alongside Stadt.
- Badass Bookworm: He's a professor after all.
- Celebrity Resemblance: Prospero is very obviously modeled after Vincent Price, from his looks to his dry wit. He comes complete with Shout Outs to numerous Price films of his, with the name Frederick Loren from House on Haunted Hill and Prince Prospero from The Masque of the Red Death.
- Deadpan Snarker: Prospero has a very, very dry wit, in keeping with the actor he's modeled off of.Daphne: You're wearing a cross?! Are you insane?Prospero: No, I'm Presbyterian.
- Happily Married: He was happily married twenty years ago. That ended ten years ago. But as of five years ago, he is happily married again. All to the same woman.
- It's Personal: One of the reasons he's accompanying Stadt on investigating is because Krolock killed his brother.
- Nerves of Steel: Nothing seems to phase Prospero whatsoever. a sadistic Great Old One warping reality around him? He just calmly asks for an explanation.
- Psychic Powers: He's a medium with minor psychic powers, including the ability to see ghosts, past events, and sense supernatural activity.
- Real Men Love Jesus: He's a devout Presbyterian, which comes in handy as his faith is needed to repel strigoi with the cross.
Maria Lucita de Moncada
A non-binary Hunter from the 14th century and former wife of Hardestadt, then called Lucian.
- Ambiguous Gender Identity: Maria felt deep within they were neither man nor woman (while being biologically female), and the story uses the pronoun 'they' for them.
- Authority Equals Asskicking: One of the highest-ranking members of the Brotherhood, and arguably their most proficient member.
- Awesomeness by Analysis: Effortlessly deduces a strigoi impersonating Lucian from the few minor, easily missed slip-ups he makes.
- Badass Normal: Maria has none of the supernatural powers of their husband, or many of his other loves, but their prowess in combat and their skill in putting down verminous supernatural creatures is equal to Hardestadt himself.
- Badass Spaniard: Maria is a fighter equal to Hardestadt in martial skill, and they're from Aragon.
- Battle Couple: With Hardestadt. Both are incredible warriors and make an incredible team when fighting together.
- Dashing Hispanic: Rather dashing, well dressed and talented, as well as being from Aragon.
- Early-Bird Cameo: Appeared in a flashback in In The Castle of the Night before their proper introduction in Loves Lost & Found, revealing they were involved with fighting back creatures at the fall of Wisborg.
- Establishing Character Moment: Quickly proves they're worthy of their mettle when they deduce and slay one of the Kraans—one of the Co-Dragons of Count Krolock—without breaking a sweat.
- Heroic Willpower: Maria was still fighting monsters despite being infected with the Black Death to the point Eliza was stunned they could even move.
- Hunter of Monsters: As proficient as Hardestadt himself in this end, regularly fighting bloodthirsty monsters and killing them as a profession.
- The Lost Lenore: A Foregone Conclusion, but Hardestadt lost them to the Black Death long ago, despite their clear love for one another.
- Religious Bruiser: In addition to their martial prowess, Maria was a very devout Catholic to the point of insisting they and Hardestadt were married in a church, something he'd usually never bother with.
A woman living in northern England in the 7th century, the ruler of Korvagat, and a storyteller and spellcaster herself. Hardestadt's wife, then called Godric.
- All-Loving Hero: Her preferred way to deal with undead monsters? Gently ease them into their fates by promising they'll be remembered.
- Friend to All Children: Hild loves the children of Korvagat and regales them with her stories frequently.
- The High Queen: The lady of Korvagat, and a noble, beautiful woman who protects her people.
- Silk Hiding Steel: Hild is sweet and gentle, but with a core of iron under it.
- The Storyteller: Hild's favorite activity? Telling and hearing stories.
- Action Girl: Kanti is a particularly skilled warrior.
- The Archer: One of her weapons of choice? Her bow, and she's an amazing shot.
- Badass Native: Kanti is a Cree woman and a skilled tracker and fighter.
- Cold Sniper: Kanti is relaxed and calm, but an exemplary sniper with her bow and arrow.
- Deadpan Snarker: She has a dry sense of humor to complement her husband's.
- Good Is Not Soft: Kanti is a very good person, but she has no hesitation slitting the throat of a trafficker who kidnapped children for dark purposes.
- Happily Married: She's Hardestadt's wife and the two are incredibly happy together.
- Knife Nut: Her other favorite weapon? Her knives.
- Pay Evil unto Evil: Kanti is not a particular believer in mercy for evil villains.
A young, mute boy from Yugoslavia who lives in an orphanage in Maryland. Integral to the plot of None Too Holy.
- Cute Mute: Never says a word, but his vulnerability and shyness only makes him more endearing to Hardestadt and the rest.
- Dark and Troubled Past: Aleksandar witnessed his own mother being murdered by his father back in Yugoslavia. Except the truth is even worse; said murder? Was committed because her mother was a vile monster who molested him at the prospect of bringing herself back as a pijavica through that atrocity.
- Dumb Struck: Was rendered mute after his mother was murdered in front of him. Thankfully, years later, it's related that he did eventually learn to speak again.
- Shrinking Violet: He's particularly withdrawn among the orphans and never says a word.
- Parental Incest: Inflicted upon him by his mother, which was the trigger for his father killing her to begin with.
- Action Girl: Mary is a particularly talented fighter, on par with Hardestadt himself.
- Ambiguous Gender Identity: She prefers female pronouns but admits she doesn't identify strongly as a woman.
- I Am What I Am: She makes no bones about being a pirate and enjoys her job immensely.
- Fire-Forged Friends: She and Eliza, through all they go through together, strike up a strong bond. Ditto her and Anne Bonney who has a strong history with her.
- Hyper-Competent Sidekick: She's one of the best aboard the Shrike and routinely shows she's just as capable in command.
- Master Swordsman: One of the finest human warriors in series and she, not Hardestadt, is the one to defeat the Big Bad of the story she's involved in.
- Number Two: Hardestadt's right hand aboard the Shrike.
- Pirate Girl: One of the most famous pirate girls, to boot.
- Retirony: She sacrifies her health, knowing she'll die soon, just before she was to retire from piracy with Hardestadt and open an inn by the sea.
- Scars Are Forever: After her first husband was murdered, the killers lashed her back, which she still has the scars of to present day.
- Subordinate Excuse: One of the reason she is aboard the Shrike and not the Ranger is she and Hardestadt are lovers.
- Sweet Polly Oliver: She disguises herself as a man named Mark aboard the Shrike.
- Sword and Gun: Her favored armaments are a good blade and her trusty pistol.
- Your Days Are Numbered: Sealing the Leash and stopping the Cthonis carries with it a hefty toll and she knows she's likely to die within just a few years as a result.
A female Irish pirate who serves aboard the Ranger,
- Action Girl: Anne has a reputation as tougher than the men she sails with. It's well deserved.
- Awful Wedded Life: Her husband James, whom she's technically still married to. He was a rake, a thug and grew jealous of her before trying to beat her. Then he betrayed the pirates, which has left Anne despising him.
- Dead Guy Junior: She names her daughter Mary, after her best friend Mary Read.
- Everyone Has Standards: Charles Vane killing prisoners deeply disturbs her and is a key factor of her choice to participate in the mutiny against him.
- Fiery Redhead: Her hair is red and she has the burning personality to match.
- Fire-Forged Friends: She, Eliza and Mary are close friends for what they've been through together and Anne cares about them deeply.
- Good Is Not Soft: Anne is a pretty laid back pirate, as thorny as she can be. She still kills her husband for all he's done without batting an eye and will kill anyone who raises hand to her or her friends.
- Master Swordsman: She's just as skilled as Mary Read and fights with expert skill.
- Pirate Girl: Maybe the most famous ever.
- Retired Badass: In the epilogue, she's grown older and lives in a quiet estate in France with her daughter. She's lost none of her edge.
- Subordinate Excuse: She remains aboard the Ranger due to being the lover of its first mate Calico Jack Rackham.
- Sweet Polly Oliver: She disguised herself as a man in the past.
- Sword and Gun: Like Mary, she prefers a blade and her trusty pistol.
- Badass Beard: It's Blackbeard. He's got one hell of a thick one.
- Benevolent Boss: He's a very laid back captain, all things considered.
- Captain Colorbeard: One of the trope namers in real life.
- Everyone Has Standards: He abhors needless killing and prefers to intimidate his quarry.
- Large Ham: He knows his ferocious reputation and plays it up, roaring and acting the devil all he can.
- The Lost Lenore: His wife Anne from when he was a poor sailor. He even named his ship after her, his 'queen.'
- Made of Iron: Takes multiple shots and sword wounds before he finally falls, fighting long after he should be dead.
- Pirate: Maybe the most famous in history.
- Punch-Clock Villain: Pirating is just a way to make a living and he's a fairly decent fellow off the clock.
- Seen It All: Nothing phases him. You see strange things out on the ocean.
- Scars Are Forever: He has a fair collection of war wounds.
- Talk Like a Pirate: He speaks with a Somerset accent, the typical 'pirate' accent.
- Terror Hero: His ferocious reputation tends to precede him. It's mostly made up, but he loves the fear it inspires and makes it less likely anyone gets hurt.
- We Used to Be Friends: He was once Benjamin Hornigold's best friend and his student. Now they're enemies.
- Catchphrase: "Fuck you, Jack." Said to Jack Rackham.
- Cold-Blooded Torture: Vane has a rep for this, not undeserved.
- The Dreaded: Everyone on the sees are terrified of Charles Vane and it's obvious to see why.
- Even Evil Has Standards: He despises rape and at the end, he cares about the other pirates, refusing to abandon them.
- Honor Before Reason: He kicks valuable treasure overboard and refuses to abandon the other pirates when the going gets tough, even when it does him no good.
- Kick the Dog: He kills several helpless prisoners in rage when he learns of Thatch's death.
- Leave No Survivors: He enjoys putting down every enemy in his path.
- Master Swordsman: One of the finest human warriors in series and she, not Hardestadt, is the one to defeat the Big Bad of the story she's involved in.
- Number Two: Hardestadt's right hand aboard the Shrike.
- Parental Substitute: he fancies himself like a father to Anne Bonney.
- Reality Ensues: What happens to a pirate captain who tosses treasure overboard and has such a brutal reputation, putting his crew in danger? They mutiny.
- Token Evil Teammate: Among the pirates, Vane is the most vicious. He's a brutal, murderous thug who has a strong mutual dislike with Hardestadt.