A coalition of the signatories of the Temporal Accords, the TDI will be formed in 2769 to safeguard the signatories' shared history. Given the nature of this work, it has a presence before its establishment in the form of temporal operatives active throughout history.
- I Did What I Had to Do/My Country, Right or Wrong: Sometimes saving the timeline means doing things that, honestly, they don't want to. Case in point, in the Tier II Transmission, you find out that Commander Nereda is forced to aid the Obsidian Order on her homeworld of Cardassia Prime in stopping a bombing by a dissident group. Doing so prevented a peaceful democratic Cardassian government from forming and saved the life of Gul Dukat's father.
- Police Are Useless: The TDI NPCs are, to a man, completely and utterly incompetent at anything to do with their job descriptions and consistently need to be bailed out by the present-day protagonists who, per the Temporal Prime Directive, shouldn't have been allowed to become involved to begin with. On at least two occasions, major TDI personnel drop their temporal beacon with their reports on them, only for said reports to be picked up by a native resident of that time period ( Scotty & Garak, to be precise ) and have a habit of showing up late to temporal distress calls or timeline alterations. See also the obvious method to inhibit Noye stealing the Annorax that they completely and utterly failed to spot: going back in time to before he stole it to disable the now-Pointless Doomsday Device (with the temporal shielding up Noye's stolen Annorax would remain around, but only so long as the temporal shielding remained up).
- Time Police: In a sense, the Time Police of the setting, being an alliance of the Time Polices of most significant powers.
- Played by Matt Winston
An agent of the Temporal Defense Initiative who has a questionable record of helping the galaxy.
- Ambiguously Human: He's human...mostly.
- Back from the Dead: He's very good at this as seen in Star Trek: Enterprise.
- Beauty Is Never Tarnished: Averted then played straight. Is horribly disfigured over the course of events. He's fine in the end.
- Big Good: Of Agents of Yesterday and "Yesterday's War", theoretically.
- Incompetence, Inc.: Daniels's incompetence leads to an entire planet dying in the first episode of the "Yesterday's War" arc. Things go downhill from there.
- Mike Nelson, Destroyer of Worlds: Accidentally gets a Romulan planet blown up trying to protect the past.
- Not His Sled: Is not Future Guy from the Temporal Cold War.
- Police Are Useless: Daniels screws up a great deal in the course of his duties.
- Stop Helping Me!: The player character can end up like Captain Archer and tell Daniels to shove off.
- Time Police: The most prominent member of the faction in the game.
- Big Damn Heroes: Is the only reason the Lukari don't have their sun destroyed.
- Heinz Hybrid: He's at least five races joined together.
- Killed Off for Real: Ends up killed when Daniels' timeship is damaged. His corpse ends up in 2154 for a short time before returning to 2410.
- My God, What Have I Done?: He's the creator of the Tox Uthat and thus (indirectly) responsible for the destruction of the Na'kuhl's sun.
- Time Police: He's not one himself, but Daniels lent him his timeship.
- You Already Changed the Past: Kal Dano is responsible for hiding the Tox Uthat for Captain Picard in "Captain's Holiday."
A Joint Task Force dedicated to stopping Tholian Incursions in local space, starting with Nukara Prime. Notable in that while the KDF and Federation are fighting Tholians on Nukara Prime, both forces are working independently and only tolerating each others' presence. Headquartered on Nukara Prime.
- Death World: Nukara Prime
- Enemy Mine: Again, the KDF and Feds aren't technically working together on this project, at least not at first. They're merely serving their own interests together. That interest happens to be throwing the Tholians out of their (contested) space.
- Mechanistic Alien Culture: Tholians are very puncutal.
- Starfish Aliens: They are crystalline, walk on six legs, are hemaphroditic, and can communicate by emmiting radiation.
A time-traveling race that becomes extremely important in the Iconian and Temporal Cold War.
- Doomed Hometown: Most of their worlds are destroyed by the Vaadwaur.
- Enemy Mine: Having to ally with the Federation against the Iconians. Deconstructed as they become enemies as soon as the Iconians are defeated.
- Jerkass Has a Point: They just want to fiddle with time to stop their own genocide while the rest of the Alpha Quadrant is doing the same.
- Planet of Hats: Played with. They aren't a time-travel focused race until events force them to become one.
- The Remnant: They have a single colony left after the Vaadwaur's massacre.
- Set Right What Once Went Wrong: Their plans for using their time ship to bring back their Empire.
- Vestigial Empire: They were once a Federation-sized power in the Delta Quadrant but were reduced to only a couple of dozen planets by the time of Star Trek: Voyager. Things went From Bad to Worse when the Vaadwaur rebuilt their own empire and decided the Krenim were too dangerous to live and destroyed all their worlds except for Kyana Prime, which phased out of reality to flee their reach.
A Krenim scientist who helped build the Annorax during the Iconian War
- Beard of Evil: His goatee morphs into a full beard when Clauda is erased. It's subverted at first as he still fights alongside the Alliance, but once he reads the information in the Annorax' temporally shielded datacore and rediscovers Clauda, it's played as straight as an arrow.
- Canon Character All Along: In STO's continuity, he's the Mysterious Figure/"Future Guy", known ingame as the Envoy. He's also played by James Horan.
- FaceHeel Turn: When he learns that he had a wife and an unborn child and he lost them due to the events of "Butterfly", he loses it, hijacks the Annorax and sets his sights on obliterating the Federation.
- Early-Bird Cameo: In the Agents of Yesterday version of Temporal Ambassador (done around level 20) he (or rather, his counterpart in an alternate timeline) shows up to explain how he helped get you where you are and what you need to do. His next appearance (or rather, his next appearance in which his identity as Noye is not itself a reveal preserved for later) is in Broken Circle (done a while after the level cap of 60 is hit), in-universe several months later.
- Grand Theft Prototype: He steals the Annorax and turns it into an Ace Custom, armed with Sphere Builder tech.
- Hate Sink: Noye is one of the most obnoxious villains in the game with his extreme selfishness, Revenge Myopia and tendency to get away scott free every time you face him due to the Cutscene Incompetence enforced on the player.
- It's All About Me: Noye is willing to wipe out species and planets to get one woman back, and allies with species that murder entire UNIVERSES. And yet he calls the Federation evil...
- Large Ham: A bit more subdued than Leeta or Hakeev, but still...! Fridge Brilliance in this case; he's had to turn to something to recover from his wife's death, and it just happened to be ham.
- Love Makes You Evil: Learning of Clauda and their unborn child makes him desperate to get them back. It's a pretty shallow excuse, as he was already a selfish jerk and the alternate Noye literally never knew said wife and thus had no emotional connection to her or reason to want her back. There is also that in both shown timelines where Noye actually did know his wife he is noticeably calmer and more rational — even the one where she was killed.
- Misplaced Retribution: He blames the Federation for the loss of his wife and child, but it's unknown if he knows why they're gone outside of the fact that it involved the Federation.
- Make Wrong What Once Went Right: He wants to eradicate the Federation from history and free the Tuterians/Sphere Builders to get Clauda back.
- Set Right What Once Went Wrong: His counterpart in the Yesterday's Enterprise timeline also desires to use time-travel to bring back his wife and get revenge for his loss — the difference is, in that timeline he lost his wife to a mundane if brutal Dominion invasion, and he's managed to figure out that his current timeline (where the Dominion stands triumphant) is itself the result of temporal interference, so his goal is to counter the interference and restore a timeline where the Federation still exists and could fight the Dominion.
- Never My Fault: He blames the Federation for having a cavalier attitude towards temporal manipulation for the near-destruction of his species, when he himself was a vocal proponent of using the Annorax even after its incursion failed.
- Not So Different: He and Annorax are very similar in many aspects:
- Both of them were Krenim that lived in Kyana Prime.
- Both were temporal scientists who built a mighty timeship to save their people's future.
- Both of them lost their wives due to a temporal incursion that went badly.
- Both of them did everything in their power to get their wives back, leaving a trail of destruction in their path.
- Start of Darkness: He lost his wife Clauda and their unborn child due to the rebuilt Annorax's temporal incursion to erase Iconia's discovery, which went horribly wrong and allowed the Borg to build a beachhead in Romulus. When the Annorax made another incursion to undo the first, it created a Close-Enough Timeline where the Tuterians were assimilated by the Borg due to them never developing the tech that protected them in the first timeline. The Annorax's temporal shield was also damaged by the Borg, so Clauda was erased before they could save her people. This also became the Sphere Builders' own Start of Darkness, as the Tuterians had to flee to another dimension to survive the Borg.
- You Sound Familiar: Marc Biagi also voices several Klingons and a Dummied Out Vorta. Since Season 19, he sounds a lot like the Mysterious Figure/Envoy, because they're the same person.
A humanoid race who, in the future, sought to manipulate history of the past (as seen in Star Trek: Enterprise).
- All of the Other Reindeer: With the Na'kuhl homeworld dying, everyone's treating them poorly - the Romulan Republic can't take them in because of the Iconaian War ravaging their world and people, the Klingons and the Cardassians are more than willing to take them on if they'll just go ahead and start becoming warriors, too, and the Federation bureaucracy is just dragging their feet.
- Cycle of Revenge: An almost-frightening similarity towards that of the Iconians and the Romulans. Time-travelling Na'kuhl get revenge on the Tholians in 2268 for the destruction of their homeworld by killing an entire Tholian bloodline. The Tholians respond two centuries later by stealing the Tox Uthot and destroying their sun.
- Doomed Hometown: More like Doomed Homeworld - the Tholians ravage their sun using the Tox Uthat, forcing them to evacuate and find a new planet.
- Earn Your Happy Ending: After the end of the Temporal Cold War, their star was reignited with the Tox Uthat in the 29th century.
- Fantastic Racism: From both the Na'kuhl and the Federation; the Feds are scared that the Na'kuhl are gonna be another Iconians and the Na'kuhl are convinced that the entirety of the Federation is evil. The Na'kuhl also utterly despise the Tholians for what they did to their star.
- Historical In-Joke: According to an in-universe blog post, a Na'kuhl temporal agent attempted to murder the Roman emperor Hadrian in 130 AD. His lover Antinous took the bullet for him.
- Man Behind the Man: In "Doomsday Device", it's revealed that they told a group of Klingons of their history in order to gain their trust. The Klingons got the information... then proceeded to laugh in their face and get rid of them.
- Not in This for Your Revolution: While the Na'kuhl and the Noye faction of Krenim have the same goals - using time travel to undo their mistakes - they initialy hate each other's guts and will attack each other. Later on Noye, in the guise of 'the Envoy' manages to weld them together along with Vorgons, the Terran Empire and the Sphere Builders into a 'Temporal Liberation Front' of factions that seek to use time-travel to achieve dominance.
- Red Eyes, Take Warning: The 29th-century Na'kuhl all have red eyes, and have become major antagonists in the post-Iconian War-era storyline.
- Screw the Rules, I'm Doing What's Right!: During the signing of the Temporal Accords, they attempt to protest it, claiming that they want a addendum to allow them to restore their homeworld, despite the damage they could cause.
- Start of Darkness: The destruction of their sun in "Stormbound", which is what inspires their use of time travel as a weapon.
- What the Hell, Hero?/Vagueness Is Coming: A Na'kuhl chews you out for failing to stop their sun's death, then vows to bounce back threatening to use "history".
- Your Terrorists Are Our Freedom Fighters: While the Krenim, Sphere Builders, and Terran Empire are more after world domination or personal revenge in their opposition to the Temporal Accords, which govern time travel and outlaw its use as a weapon, the Na'kuhl oppose the Accords and fight the treaty's backers because their homeworld pre-Accords suffered Apocalypse How at the hands of time travelers and the committee that wrote the Accords and decided which timeline was "correct" refused to let them fix this incursion (ostensibly because the Na'kuhl homeworld's destruction was one of the key events leading to the Accords' creation in the first place). The Player Character can express sympathy for this viewpoint, or not, when they time-travel to the signing of the Accords in the 28th century, then during subsequent missions the Na'kuhl launch various malicious temporal incursions (including attempting to assassinate the President of the Federation) in hopes of creating a timeline sans Accords or Temporal Defense Initiative.
- Ascetic Aesthetic:Tholian ships are very minimalistic on the inside, with geometrical rooms and triangular hallways and consoles.
- Collector of the Strange: They loot countless starships and artifacts from different time periods and dimensions. They're technically the main source of ships from the past, the future and the Mirror Universe, like the Wells timeships of the 29th century and their Evil Counterpart, the Mobius temporal destroyer.
- Fantastic Racism: They dislike most races in the galaxy, in part because they're very different and see them as lesser beings. Some Tholians are full-blown Absolute Xenophobes and try to exterminate all life they consider beneath them. There are some exceptions, as the Tholians are willing to trade wares from time to time, like their famous Tholian Silk.
- More than Three Dimensions: Some novels imply that that the Tholian Assembly exists in more than just our time/space due to the weakened dimensional barriers in their homeworld.
- Only Sane Man: The Tholian delegate to the Temporal Accords signing ceremony can come off as this to players who dislike the story arc, since his government authored a rejected amendment to ban time travel entirely rather than trying to cherry-pick which temporal incursions are acceptable.
- Realpolitik: Really, this is the best summary of their history in relation to other species: they're exceedingly protective of their own territory and seem to want to claim dominion over all Y-class planets (the only ones they can live on: they're quickly killed by exposure to Earthlike conditions), but on the other hand they're perfectly willing to work with other factions when it isn't in conflict with those goals.
- Silicon-Based Life: They are spider-like beings who can only exist in near volcanic temperatures. They wear armored spacesuits in Earth-like environments. Lower temperatures will fracture their carapaces and eventually kill them.
- Tyrant Takes the Helm: In an alternate timeline where the Enterpise C never made its Heroic Sacrifice, the Dominion defeated the major factions of the Alpha and Beta Quadrants. After the Assembly formed a non-aggression pact with the Dominion, they took over the Beta Quadrant and forced the survivors of the Dominion War to become Servant Races in exchange for survival.