Starfleet
- Amicable Exes: Averted with him and his ex-wife Jeanine Vinueza. He still loves her and she loathes him.
- Big Good: Of a flawed Broken Ace sort.
- The Captain: Despite being a commodore, has this role.
- Gilded Cage: His imprisonment at the Klingons' hands, at least by their standards.
- I Have Your Wife: Gorkon quotes The Usual Suspects about Reyes' girlfriend having something unfortunate done to her if he doesn't cooperate.
- Knight in Sour Armour: Heroic but also very cynical.
- Morton's Fork: Can either lie to his wife or reveal classified information.
- No Kill like Overkill: Is the first Starfleet officer we've ever seen carry out General Order 24.
- Make It Look Like an Accident: Said word for word to Ganz when he makes a deal with the crime boss to sabotage the Klingon's ship.
- My God, What Have I Done?: When he orders General Order 24 on Gamma Tauri IV after his ex-wife is killed by the Shedai.
- Orbital Bombardment: Orders this after the destruction of a Federation (sort of) colony.
- Screw the Rules, I'm Doing What's Right!: When he gives Pennington the information about his ordering the destruction of a world. He knows its career suicide and may result in him spending the rest of his life in jail.
- To Be Lawful or Good: Has a hard time reconciling his duty to Starfleet with the goals of Project Vanguard.
- The Captain: Becomes this de facto after Reyes is arrested then captured.
- Consummate Professional: Carries on his orders with due professionalism.
- Only Sane Man: Is a Consummate Professional in a story filled with Bunny-Ears Lawyer types.
- Rank Up: Becomes commander of the station. After Reyes is court martialed.
- The Watson: Serves as this to Diego Reyes at the start.
Vulcan Starfleet Intelligence officer of Starbase 47, living in self-imposed exile from Vulcan due to her being a val'reth- she holds the katra of her former fiance, whom she killed in the heat of pon farr, against her will; in a lesbian relationship with Anna Sandesjo/Lurqal. T'Prynn also appears in the Pocket DS9 Mission Gamma novel Lesser Evil.
- Arranged Marriage: T'Prynn's did not go well. The ritual combat that was invoked when she filed for divorce also didn't go well. To explain: T'Prynn rejected her appointed mate, Sten, whom she never loved, and decided instead to choose her own companions. Sten was unwilling to release T'Prynn from her betrothal and invoked ritual combat in an attempt to force her to submit. T'Prynn refused; she killed him in the combat that followed. But before he died, Sten forced his katra into T'Prynn's mind.
- The Atoner: By the end of Star Trek: Vanguard:It is likely I will never balance the scales of my own guilt and virtue. But that does not absolve me of my responsibility to try.
- Bury Your Gays: Dies in the future in a transporter accident.
- Citizenship Marriage: With Tim Pennington, as a part of one of her many undercover schemes. She needs to get herself off of Vulcan, and requires Earth citizenship to avoid a specifically Vulcan identity check. She therefore marries Pennington, the nearest convenient Earther, and who has agreed to help her.
- Court-martialed: For her actions early on, which sees her demoted two steps in rank and stripped of her position as Intelligence Officer.
- Deadpan Snarker: At times. Particularly notable when she asks if Starfleet personnel assigned to a super-freighter should be given first-class accommodations:"No of course not. Such generosity from Starfleet would be certain to draw suspicions. Steerage it is then".
- Determinator: Never submits to Sten despite decades of his attempts to get her to do so.
- Foregone Conclusion: Dies on the USS T'Plana-Hath in a DS9 novel.
- Heroic BSoD: Has one of these after her career is destroyed and her lover killed.
- Hidden Depths: Is a gifted jazz pianist.
- Honey Pot: Uses herself as this to turn "Anna."
- Insanity Defense: During the darkest period of her career, partway through the Star Trek: Vanguard series, she points out it's the only plausible defense she could give for her latest actions, though she doesn't pursue it
- Interspecies Romance: A homosexual relationship with Anna Sandesjo/Lurqal (a Klingon spy disguised as a human).
- Mind Rape: Is a victim of this at the hands of her betrothed, Sten. He forced his katra into her mind at the moment of death. It effectively forces her to deal with his ghost every day.
- Pet the Dog: Frees Cervantes Quinn from his obligations to Starfleet and his crime lord boss after he rescues the Sagittarius
- Saved by Canon: In an interesting example of a character being Saved by Canon for the moment, but Doomed by Canon in the long run, T'Prynn can't die at any point in the Star Trek: Vanguard series, even when she's in a coma due to Mind Rape, because she's going to die in a transporter accident eighty years later, as shown in Flash Back in the Star Trek: Deep Space Nine Relaunch novels.
- Screw the Rules, I Make Them!: Takes advantage of her power as a Starfleet intelligence officer to do this a lot.
- Adventurer Archaeologist: Comes with investigating the Shedai.
- Broken Pedestal: His relationship with Starfleet, basically.
- Heroic Sacrifice: Mortally wounded, he remains behind to set off Vanguard's self-destruct system.
- Secret-Keeper: One of the few individuals who knew about the reason behind Starfleet's investigation of the Meta-Genome.
- Rebellious Rebel: Is still a lieutenant because he has severe issues with authority.
- Wide-Eyed Idealist: Believes this about the Federation.
- Wrong Genre Savvy: Unfortunately, Ming Xiong is in the darkest incarnation of Star Trek yet.
- Cool Old Guy: Close to retirement age but still able to pull off medical miracles.
- Not Quite the Right Thing: His attempt to help T'Prynn results in her life collapsing.
- Pulling the Thread: Investigating T'Prynn's headaches results in her career coming undone and attracting the attention of Starfleet Intelligence.
- Spanner in the Works: Makes a lot of his plans based around leaving his position to his subordinate. Then she announces that she wants to serve on a starship.
- Family Versus Career: Is aware that Diego wants a family and children perhaps better than he is.
- Hello, Attorney!: A very hot JAG officer.
- Loved I Not Honor More: Averted as her plans to prosecute Reyes turn out to be a plan to defend him.
- Screw the Rules, I'm Doing What's Right!: Is interested in doing everything she can to protect Reyes after he torpedoes his career.
- Second Love: Is this for Reyes. Tries this after Reyes "dies." It doesn't work out.
Federation
- "Ass" in Ambassador: Has no real interest in doing this function and is really just there to look after Starfleet's role in the Meta-Genome.
- Deadpan Snarker: Has a wicked sense of humor.
- Everybody Knew Already: Jetanian already knew that Anna was a Klingon spy despite T'Prynn's best efforts to keep it secret.
- Knight in Sour Armour: He admits that while serving the people is an honour, he can't stand people themselves.
- Reassigned to Antarctica: A rare self-inflicted example. He leaves Vanguard station to build the colony on Nimbus III, and remains there even after it's clear that the project is a failure.
- Starfish Alien: Is an enormous praying mantis.
- Trademark Favorite Food: Denebian shellfish broth is his.
Civilians
- Brave Scot: Is Scottish and does quite a few heroic things (and some unsavory ones too).
- Citizenship Marriage: Has one of these with T'prynn.
- Hot Scoop: Is a very attractive news reporter.
- Intrepid Reporter: Tries to dig into Gary Mitchell's death on Delta Vega, then tries to find out about aspects of Operation Vanguard that may have caused his lover's death.
- Lost Lenore: Is devastated by the loss of his lover Orianna and the subsequent cover up.
- Odd Friendship: His relationship with Cervantes Quinn. Arguably with T'Prynn.
- Saved by Canon: The Pennington School for aspiring authors is named for him, so we know that he’ll eventually re-establish his reputation.
- Sympathetic Adulterer: Played with. His affair with Orianna is less than honorable given his wife, Lora, seems to have him dearly.
- Unwitting Pawn: T'Prynn uses him to cover up events in the Taurus Reach, destroying his career.
A trader and independent soldier-of-fortune who becomes tangled up in Project Vanguard, the morally ambiguous Starfleet operation detailed in the Star Trek: Vanguard series. He tries several times to turn his life around, escaping from alcoholism and ties to criminal syndicates only to dip back in again when he suffers another emotional blow.
- Action Survivor: Although he becomes far more of a traditional action hero during the middle of the series, during his time as a asset of Starfleet Intelligence. Sadly, Quinn is very much in Butt-Monkey territory...and not the humorous sort of Butt-Monkey, either.
- The Alcoholic: The reasons why were explained mid-way through the series. He then recovered for a time, only to fall back into alcohol towards the end, after suffering intense personal loss.
- Cool Ship: The Rocinante (no, not that one).
- Dark and Troubled Past: Used to be a mercenary for dilithium mining companies. It turned out they were of the Armies Are Evil kind.
- Expy: Of the soldier-of-fortune characters from Star Trek: The Original Series, like Harry Mudd or Cyrano Jones. Also a bit of a deconstruction.
- Hidden Depths: Actually an extremely capable Marine and guerilla fighter.
- Lovable Rogue: Is a criminal but mostly a nice guy.
- Odd Friendship: With Tim Pennington, a formerly famous journalist.
- Space Trucker: Is a civilian cargo ship pilot and trader in the Star Trek universe.
- Affably Evil: He's a ruthless gangster and crime lord but quite reasonable as such things go.
- Friendly Neighborhood Gangster: How the people on the Vanguard view him. He's not really that friendly.
- Make It Look Like an Accident: Is told to do this with a bit of sabotage by Starfleet.
- Becomes an Orgy of Evidence instead as his saboteurs don't just sabotage one thing but sabotage about a 1000 things that immediately clues the Klingons into the fact they were sabotaged.
- Shame If Something Happened: Is quite fond of making these sorts of pronouncements.
Klingons
- Anguished Declaration of Love: Gives one to T'Prynn and it doesn't get acknowledged.
- Bury Your Gays: is killed for betraying the Klingon Empire.
- Butch Lesbian: Is a Klingon and lesbian, so it comes with the territory.
- Double Agent: Was sent to infiltrate Starfleet but was turned by T'Prynn through the manipulation of her feelings.
- Magic Plastic Surgery: Appears to be a human Hispanic woman. She's actually a Klingon.
Alien Races
An advanced race who once controlled a vast empire in the Taurus Reach region. They were roused from hibernation in Star Trek: Vanguard, when the Federation stumbled across their technological relics. Finding younger races meddling on their worlds, the re-awakened Shedai lashed out in vengeance.
- Abusive Precursors: They left self-destruct systems embedded in the planets they once ruled before going into hibernation. Finding some of these planets overrun with younger species, the re-awakened Shedai Wanderer is quick to put a stop to it with an Earth-Shattering Kaboom or two.
- Bizarre Alien Biology
- Fantastic Caste System: The Shedai are divided between the ranks of the Nameless, each confined to only one body, and the elite Serrataal with individual names, e.g. The Maker, The Wanderer, The Myrmidon, who can take multiple forms simultaneously.
- The Right of a Superior Species: The Shedai word for peoples outside their hegemony doubles as a synonym for "base criminals" or "uncivilized beings".
- Scary Dogmatic Aliens
- Sufficiently Advanced Aliens
- Super Smoke: They can shed their corporeal form at will.
- There Is No Kill Like Overkill