* CreepyCute: The Ghost fires/[[WillOTheWisp Will o' wisps]].
* EpilepticTrees: The origins of Xix. [[spoiler: Everything that is setup about his identity through the first 100+ chapters of the story was proven to be either a misunderstanding, or flat-out [[RedHerring misdirection]].]]
* HarsherInHindsight: Nearly everything and everyone about Manhwa/ImmortalRegis that comes back in Cavalier of the Abyss has gotten a whole mess of DarkerAndEdgier paint added to it.
* IronWoobie: Ninurta Noah is ''the'' most miserable character in the story, only rivaled by Nex himself.
** [[spoiler: Siana throughout the story gets put through the ringer as well.]]
* MoralEventHorizon: Nex gives the order the complete extermination of a town because the ruler was a traitor and since he lead the town to prosperity they might be followers.
** [[spoiler:Later we see him order his wife's death just to draw out Ninurta who he views as a traitor.]] Subverted to an extent later on, as it appears tough that it is just an excuse to [[spoiler: get her clan out of the way, as they have become increasingly more influential.]]
** Iffrita herself is heavily implied to have crossed this - [[spoiler: as a revenge for her mother, she stole one of the children of Nex and Serin Ninurta a.k.a. the ''real'' prince Xix, then has Mimir disguise Ninurta as her own child (in exchange for her own right horn), as well as apparently framing Serin for false charges of treason, effectively setting in motion Ninurta's TraumaCongaLine [[GoneHorriblyWrong without even realizing it]].]]
* TheScrappy: Seon Yu thanks to his NeverMyFault and ChronicBackstabbingDisorder tendencies which tend to make things worse and worse for the protagonists every time he appears.
* TrollingCreator: A ''lot'' of chain yanking, considering the series did essentially 180 from where it had stood at the end of Immortal Regis. The author likes to drop hints and clues in every which direction, but never giving a clear answer; this is partially why the manhwa is so confusing for the first 20 or so chapters.
* YankTheDogsChain: So far the the Dragon Festival Side story is looking like it [[spoiler: with the story ends with Yuan getting her desire of dancing with Xix fulfilled and the two of them seeing a Dragon spirit that is supposed to grant the wish she made, which was for happiness for everyone. A pretty happy ending... until it is revealed that the last couple to see a dragon and dance was [[FallenHero Nex]] and [[AndIMustScream Serin]]. ]]
** Ninurta made it in time to call for his mother's execution to be stopped. [[spoiler:She ends up dying in front of him.]]