History Characters / HonkaiStarRail

* AmbiguousSituation: Her true nature is left unclear after Aventurine reveals that [[spoiler:Acheron is likely not a Galaxy Ranger and in fact is probably an Emanator, though he's not sure which Aeon she's tied to. Then again, it's not certain if Aventurine is [[UnreliableNarrator telling the full, or even partial, truth]]]]. Given her past involving what appears to be IX, it's implied ([[spoiler:and confirmed as of ''Cats and Piegeons'']]) that she's a Self-Annihilator, someone who gazed at the Nihility and lost part of their selves, taking the "meaning" of their lives - and especially the few that can "single-handedly withstand the encroachment of Nihility on their existences," which causes the road she walks to be like a shadow of IX cast in the world. As far as her being a Galaxy Ranger, she considers herself to be in the role of one, but not a fully committed one, and she does not follow the Hunt like most of them do. [[spoiler:During his call with Black Swan, Boothill claims she's an imposter (as far as being a member of the Galaxy Rangers).]]

** Her allias in Chinese and Japanese, respectively "Huángquán" and "Yomi" (both readings of 黄泉), are names of the underworld in [[Myth/ChineseMythology their]] [[Myth/JapaneseMythology respective]] myths. Meanwhile, in English, "Acheron" is the name of a river that serves as the entrance of Hades in Myth/ClassicalMythology. The meaning becomes more pronounced in "Rondo Across Countless Kalpas" video where Black Swan indirectly describes Acheron's memories as "a silent abyss, filled with those who drowned in it" - Acheron's mind is a veritable ''underworld''.
** Her birth middle name, [[spoiler:Bosenmori (忘川守), is made of the kanji for "forget" (忘), "river/stream" (川) and "guard" (守), fitting for how she fulfils the role of {{Shinigami}} and guides souls in the PurgatoryAndLimbo manifestation of IX]].

** The scene where [[spoiler:Acheron awakens the Trailblazer from the DreamWithinADream, reaching out for their hand as they fall from Penacony's sky,]] is one big reference to the scene of Mei reaching out to Kiana in "Lament of the Fallen".

** Emanators of Nihility have natural resistance to the effects of other Paths. [[spoiler:This allows her to escape the DreamWithinADream easily and contact Black Swan to rescue her and get her to rescue the rest of the Astral Express in turn, saving them from being forever lost in the Dreamscape.]]

* OnlyKnownByTheirNickname: Her announcement post states that "Acheron" is but an alias she goes by, and no one knows her real name. [[spoiler:She eventually reveals her true name is Raiden Bosenmori Mei.]]

* PersonOfMassDestruction: She's strong enough to unleash a WorldWreckingWave capable of shattering entire dreamscapes.

** Her Ultimate line in Japanese is a haiku: 涙雨、降りて溢るる、渡り川... During her battle against Aventurine, she adds 2 more lines: 黄泉路を行けず、常世還らむ[[labelnote:Full meaning]]"Rain of tears, they fall and overflow the river... the path to the underworld (Yomi) is inaccessible, returning [you] to the mortal world" (paraphrased in English translation as "I wish to mourn the departed, weeping like rain, to swell the crossing stream...as the tide arrives, leading you back home.") Notably, she also sheds a SingleTear as she's reciting this.[[/labelnote]] These are a reference to a tanka poem in Kokin Wakashu, by Ono Takamura: 泣く涙雨と降らなむわたり川水まさりなば帰りくるがに[[labelnote:Full meaning]]"As [I] cry, rain falls onto the stream, [I] shall return as the water rises"[[/labelnote]].

* WhiteAndRedAndEerieAllOver: Her "other form", as seen in the "Rondo Across Countless Kalpas" trailer, her Technique and Ultimate, has her color scheme turning into mostly white and red, with her hair turning white and her right arm bared but colored blood red, complete with red and white flowers growing on her body. This is part of her backstory involving demonic beings.

** When he realizes he's speaking with Black Swan and not Acheron over the phone, his first assumption is that she's there to be Acheron's bodyguard, so he immediately offers to put a bullet in Black Swan's head and asks her to clean her forehead in preparation for it. [[spoiler: Turns out he has a pretty good reason to be off his rocker too.]]

* PapaWolf: [[spoiler:The motivation for his RoaringRampageOfRevenge against the IPC, as they killed his family.]]

* HeroicSacrifice: [[spoiler:In order to help the Astral Express escape the innards of the Giant Sting's belly, Argenti plans to launch himself out of the train and use his spear to stab the bug's stomach to force it to vomit the crew out, though he does assure the Trailblazer he will try to make it out alive as well. After the Astral Express crew successfully escape, Argenti is seemingly never seen or heard from again... [[SubvertedTrope then afterwards texted the Trailblazer asking if they're okay, much to their and March's relief]]. His survival is explicitly confirmed in 2.2, where the Astral Express crew has to fight him again as a part of competition.]]
* HeroOfAnotherStory: As a warrior travelling the universe following the traces of a missing Aeon, saving people and solving various crisises along the way, Argenti is doing pretty much the same thing Astral Express is; only unlike the Express, most of his heroics happen off-screen, and the players only get to hear about a small fraction of them.
* InexplicablyAwesome: Argenti has an uncanny ability to get in and out of places that would spell death for anyone else. [[spoiler:In "Night of Universal Hallucinations", he jumps out of the Astral Express into the stomach of a giant bug with no helmet and no spaceship, and shortly after texts the Trailblazer with news that he's fine. In Penacony, he enters the realm of Nihility - something that ordinarily requires getting slain by a Self-Annihilator - and leaves with Aventurine in tow.]] No explanation is ever given as to how he accomplishes this.

* OffscreenMomentOfAwesome: [[spoiler:In 2.2, he's the one who found and rescued Aventurine from the Primordial Dreamscape, a place where the Nihility taint is so strong it completely broke Aventurine's Cornerstone. How he managed to reach the place in the first place to rescue Aventurine ''and'' got out isn't elaborated upon]].
* RecurringBoss: The Express crew first battles him in 1.5 on the Astral Express, [[spoiler:and then in 2.2 on Penacony as a part of [=SoulGlad=] Festivity Auditions.]]

* UnexpectedCharacter: Safe to say nobody expected him to show up [[spoiler:during the 2.2 story, as the reigning champion of the pageant, forcing a miniboss encounter. He's also tied to Aventurine's return to reality.]]

* ItAmusedMe: As a follower of the Path of Elation, he does whatever he feels is personally amusing. This includes funding a massive gaming tournament just so [[spoiler:a little girl can see their friend once again]].

* RealityWarper: Stellarons harness Imaginary Energy, i.e. the very energy which sustains reality and its phenomenons. One Stellaron freezes an entire planet along with a horde of the Antimatter Legion -- an entire army blessed by Nanook, who is also this trope. Another Stellaron can affect the immortality blessing of Yaoshi on mortals, while the third one encountered can stabilize a section of the Memory Zone to form a peaceful Dreamscape, implying Stellarons might be this trope on a scale comparable to [[PhysicalGod Aeons themselves]].

* SkippableBossFight: [[spoiler:In Penacony, if you explain to him why you need to win the Festivity Auditions (which he happens to be the defending champion of), he lets you pass without a fight and bids you good luck.]]

* CosmicHorrorStory: [[spoiler:Formally the protagonist and presumed only survivor of one. Now traveling the universe seemingly with the day job of preventing other cases from happening, or cleaning up after they have.]]

* {{Revenge}}: According to his introduction post, he has a score to settle with the [=IPC=] with his primary target being Oswaldo Schneider.

* GameplayAndStorySegregation: As of v2.1, despite otherwise being on friendly enough terms with the Trailblazer that they can even invite her to take a group photo along with other playable characters at a Hanu-themed photo stand-in at Clock Studios Theme Park, she does not send any daily messages to the player if they have her in their roster. This contrasts towards [[spoiler:Jingliu and Tingyun, who do not send daily messages due to story reasons[[note]]canonically, Jingliu never meets the Trailblazer, while "Tingyun" is Phantylia in disguise (therefore was never on friendly terms with the Trailblazer)[[/note]]]].

** [[spoiler: Sparkle repeatedly offers a prized possession as a gift, the "Mutually Assured Destruction Button." That she promises when pressed, will completely obliterate herself and the Penacony dreamscape. For a moment Aventurine is incredulous that she would be allowed to bring such a destructive device anywhere near Penacony, but then realises that with her outlandish claims and silly persona, it could actually be a case of CrazyEnoughToWork.]]

* AmbiguousSituation: Her true nature is left unclear after Aventurine reveals that [[spoiler:Acheron is likely not a Galaxy Ranger and in fact is probably an Emanator, though he's not sure which Aeon she's tied to. Then again, it's not certain if Aventurine is [[UnreliableNarrator telling the full, or even partial, truth]]]]. Given her past involving what appears to be IX, it's implied ([[spoiler:and confirmed as of v2.1]]) that she's a Self-Annihilator, someone who gazed at the Nihility and lost part of their selves, taking the "meaning" of their lives - and especially the few that can "single-handedly withstand the encroachment of Nihility on their existences," which causes the road she walks to be like a shadow of IX cast in the world. As far as her being a Galaxy Ranger, she considers herself to be in the role of one, but not a fully committed one, and she does not follow the Hunt like most of them do. [[spoiler:During his call with Black Swan, Boothill claims she's an imposter (as far as being a member of the Galaxy Rangers).]]

* MeaningfulName: Her name in Chinese and Japanese, respectively "Huángquán" and "Yomi" (both readings of 黄泉), are names of the underworld in [[Myth/ChineseMythology their]] [[Myth/JapaneseMythology respective]] myths. Meanwhile, in English, "Acheron" is the name of a river that serves as the entrance of Hades in Myth/ClassicalMythology. The meaning becomes more pronounced in "Rondo Across Countless Kalpas" video where Black Swan indirectly describes Acheron's memories as "a silent abyss, filled with those who drowned in it" - Acheron's mind is a veritable ''underworld''.

* UnspokenPlanGuarantee: He always has one or two backup plans in place, but rarely tells anybody

* WeirdnessMagnet: She's often regarded as this, with both herself and others commenting that seemingly wherever she goes, dynamic and mysterious events are sure to occur.

* OffscreenMomentOfAwesome: [[spoiler:In 2.2, he's the one who found and rescued Aventurine from the sea of Nihility. How he managed to reach the place in the first place to rescue Aventurine ''and'' got out of there isn't elaborated upon]].

* EarlyBirdCameo: He was first name-dropped in one of Simulated Universe: Swarm Disaster's occurences, "Knights of Beauty to the Rescue". Most of the time, choosing to accept his help (among other knights) will grant you 3 Blessings of your current Path.
* EncounterRepellent: His Technique inflicts Daze on nearby enemies in the overworld, which will make them stop pursuing the party. Attacking them in this state will inflict damage on all enemies equivaent to Argenti's Attack stat on the first turn, and recover 15 energy for him.

* LargeHam: If his [[https://www.youtube.com/watch?v=PhqU5X_sMPA trailer]] is anything to go by, Argenti is truly grandiose in just about everything he does.

* UnexpectedCharacter: Safe to say nobody expected him to show up [[spoiler: during the 2.2 story, as the reigning champion of the pageant, forcing a minibos encounter. He's also tied to Aventurine's return to reality.]]

* {{Revenge}}: According to his introduction post, he has a score to settle with the [=IPC=].

* OnlyKnownByTheirNickname: Her announcement post states that "Acheron" is but an alias she goes by, and no one knows her real name.

* {{Revenge}}: According to his introduction post, he has a score to settle with the [=IPC=]. [[spoiler: The IPC incinerated his entire family, including his two year old daughter, in order to access minerals on his home planet. Then they covered it up as an accident. In particular, he's looking for their head of Marketing, Oswaldo Schneider.]]

* GameplayAndStorySegregation: Argenti enters the SoulGlad Festivity Auditions as the defending champion. This doesn't stop the player from using their own Argenti in the competition fights and even in the [[MirrorMatch boss fight against him]].

* RecurringBoss: The Express crew first battles him in 1.5 on the Astral Express, [[spoiler:and then in 2.2 on Penacony as a part of SoulGlad Festivity Auditions.]]

* RecurringBoss: The Express crew first battles him in 1.5 on the Astral Express, [[spoiler:and then in 2.2 on Penacony as a part of competition.]]

* HeroicSacrifice: [[spoiler:In order to help the Astral Express escape the innards of the Giant Sting's belly, Argenti plans to launch himself out of the train and use his spear to stab the bug's stomach to force it to vomit the crew out, though he does assure the Trailblazer he will try to make it out alive as well. After the Astral Express crew successfully escape, Argenti is seemingly never seen or heard from again... [[SubvertedTrope then afterwards texted the Trailblazer asking if they're okay, much to their and March's relief]].]]

* {{Revenge}}: According to his introduction post, he has a score to settle with the [=IPC=]. [[spoiler: The IPC incinerated his entire family, including his two year old daughter, in order to access minerals on his home planet. Then they covered it up as an accident.]]

* ConnectedAllAlong: A post-event memory bubble reveals that [[spoiler:he's an acquaintance of Sampo as a fellow Masked Fool]].

** The scene where [[spoiler:Acheron awakens the Trailblazer from the DreamWithinTheDream, reaching out for their hand as they fall from Penacony's sky,]] is one big reference to the scene of Mei reaching out to Kiana in "Lament of the Fallen".