[[folder: [[spoiler: The Clock/The Archive]]]]
* AIIsACrapshoot
* BecauseDestinySaysSo
* BiggerBad: To Brain Trust
* EldritchAbomination

[[folder:Kyouji Kagami]]
!!! Voiced by: Creator/TakahiroSakurai (Japanese), Joey Hood (English)
Originally appears as someone from Babylon City who is working for Makubex for reasons of his own. Has a thing for Himiko, and ''knows things'' that the rest of the cast does not. Fights with shards of mirrors.
* AffablyEvil: While Akabane is genuine in his own way, Kagami is ambiguous in his evilness
** He flirts with Himiko during the Tag game after the Kiryuudo incident. It's harsher in hindsight considering [[spoiler: he intends to sacrifice her to revive the Voodoo King, though he did seem sad that she rejected him]]
* AGodIAm: [[spoiler:Basically declares that he is the embodiment of the Limitless Fortress in the final arc.]]
* BigBad: Competes with the Voodoo King for this title in the final story arc.
* {{Bishonen}}: Ban notes this guy could be the head of a host club.
* DragonWithAnAgenda: To Makubex
* HiddenAgendaVillain: It's a secret up to the second to last major arc [[spoiler: Where he reveals Himiko is the necessary key to get back to Babylon City]].
* [[spoiler: KilledOffForReal]]: [[spoiler: By Akabane]]
* ImprobableWeaponUser: He fights with mirror fragments.
* MasterOfIllusion: Not to the degree of [=MakubeX=], but one of his favorite tricks is using a cloud of microscopic glass shards to create holograms of himself.
* MeaningfulName: Kagami, of course, means mirror, which is an obvious reference to his powers and fighting style. However, it becomes even more meaningful in the final arc, where it's revealed that [[spoiler:Kagami is a physicist who helped to create the entire [=GetBackers=] universe to begin with. And the theory he developed that led to the creation of that universe was called ''The Magic Mirror Effect''.]]
* [[spoiler: NoHoldsBarredBeatdown]]: [[spoiler: Gets one from Ban, but since he sacrificed Himiko, he really deserved it]]
* ShadowArchetype: He's this to Akabane; it's been specifically noted that he was put in white to contrast against Akabane's black. Played with [[spoiler:in the fact that while their appearances are different, their personalities are very similar]] also inverted [[spoiler:in that the "dark one" kills the "light one."]]

[[folder:Dr. Amano]]
A manga-only character, [[spoiler: she's Ginji's "mother"]]. It's... complicated.

[[spoiler:She's head of the team which created the dimension where the Limitless Fortress exists.]]
* AGodAmI: An interesting take on the trope. [[spoiler:When the dimension containing Mugenjou began growing on its own, beyond the control of her team, she had plans to "format" the dimension like a hard drive. Thanks to Ginji, she put away those plans.]]
* CloningBlues: Averted. [[spoiler:When her son died, although it is possible to create a clone to replace him, she knew that the clone would never be a true son to her. Hence, she created an AlternateUniverse version of him, who we know as Ginji.]]
* IllGirl: [[spoiler: Has poor eyesight]].

[[folder: The Specialist]]
Another manga-only character. The bunny girl. A scientist of some sort, with a connection to the Brain Trust. Probably has the best idea as to what the hell is going on, and has apparently told Akabane parts of it. Also known as "the Professor".

Her real name is ('''massive''' spoiler) [[spoiler:Makube]].
* MadScientist
* NotSoMinorRole
* OlderThanTheyLook
* PetTheDog: Gives Emishi, Shido and Ginji pills that boost their energy, even though she's with [[GodAmI BrainTrust]].
* RedEyesTakeWarning
* [[spoiler: TomatoInTheMirror]]: [[spoiler: her name is Makube, and Makubex is her creation]]