- "You cannot use someone else's fire; you can only use your own. And in order to do that, you must first be willing to believe you have it."
Everything's the same, except Chara survived the poisoning...and all the many repercussions of that fact.
The books of the series are:
1. someone else's fire: Chara is dying. Asriel has a secret to keep.
2. somebody out there needs you: Chara is suffering from a mysterious ailment. Another human recently fell, though, and they might have some answers.
3. love does not make me gentle or kind: Asriel is worried about Chara. Prase thinks this is going too far.
4. the subtle difference between holding a hand and chaining a soul: Chara has something to prove to Asriel.
Side story: live inside a green moment: Asriel and Chara celebrate having patched up their relationship.
5. a wish you tell a star and no one else: Asriel prepares for his coronation, and something else as well.
6. you in your veil and your pale white dress: Chara figures some things out and prepares for their wedding.
Side story: seal our lips until we're found: Asriel and Chara enjoy their wedding night.
7. under my skin, there will be flowers: Chara makes good on their promise to protect Asriel.
8. to rest in crypts and wake in gardens: Chara and Asriel meet Frisk.
9. we light ourselves up from the deepest of pits: Asriel prepares to change the world forever. Chara has a secret to keep.
Be aware that, like most Undertale fan works, there will be massive unmarked spoilers for the source material.
you can only use your own contains examples of:
- Absent-Minded Professor: Liron.
- Abusive Parents: Most of the fallen humans had them.
- Affluent Ascetic: The Dreemur castles are both very simple, comfortable homes.
- A Good Way to Die: Chara's suicide in chapter 9 of we light ourselves up from the deepest of pits is meant to be this. They're content with their life, their family will be okay, they don't really want to go to the surface, and they finally figured out a painless, foolproof way to kill themself. Asriel's still not having it, though.
- all lowercase letters: The titles of each story, as well as that of the series itself, are stylized this way.
- Anger Born of Worry: Asriel is prone to this, invariably directed at Chara. It eventually devolves into codependency. He gets better.
- Arc Words: Variations of "it wouldn't be so bad, being your heart".
- live inside a green moment has its own Arc Words: "you can't keep your hands to yourself."
- Beautiful Dreamer: love does not make me gentle or kind opens with Asriel waking up to find Chara still asleep and spending a few paragraphs discussing how peaceful they look.
- Big Eater: Rufus. Astis. Frisk.
- Broken Bird: Chara, at times.
- Cast Full of Gay: Most of the characters are LGBT+. Justified in that less-than-privileged people are far more likely to climb the mountain.
- Childhood Friend Romance: Asriel and Chara.
- Commonality Connection: Chara gains Frisk's trust by showing them their Self-Harm scars, proving that Frisk isn't alone in their troubles.
- Coupled Couples: Astis/Liron and Innig/Rufus, later on.
- Cruel and Unusual Death: Buttercup poisoning would kill a monster quickly, but it's one of the most painful ways for a human to die, and Chara doesn't realize this when they're planning their suicide. In fact, their death ends up dragged so long that Asriel has time to talk them out of it.
- Dark and Troubled Past: Every single fallen human.
- Declaration of Protection: Chara becoming Asriel's honor guard.
- Dissonant Serenity: Chara experiences something similar in we light ourselves up from the deepest of pits on the morning of the attempt to break the Barrier, during which they plan to kill themself. They muse for a bit on how both of their past suicide attempts were terrifying, but now they only feel calm. While no one else notices the dissonance which isn't unexpected, since they have no plans to open up about the fact that they're suicidal, Chara manages to unnerve themself a bit.
- Dramatic Irony: In a wish you tell a star and no one else, Chara telling Asriel that they won't be able to bear his children becomes this when the reader realizes that the really horrible period they suffered not long before this moment was actually a miscarriage, and that neither of the two ever realized it.
- Driven to Suicide: Chara. Twice, or three times if you count the one before the start of the series. Asriel ends up saving them every time.
- Earn Your Happy Ending: The cast goes through a lot, everyone has pain to work through, but in the end everyone lives and monsters go free.
- Ermine Cape Effect: Asriel is very fond of elaborately decorated formalwear, in contrast to Chara's more Simple, yet Opulent tastes.
- Eternal Love: Chara suggests that they and Asriel could have this in the last chapter of we light ourselves up from the deepest of pits if he absorbs their soul. He refuses.
- Fate Worse than Death: Chara considers seeing their blood family again, even in passing, to be this. No exaggeration whatsoever. They actually attempt suicide to avoid any risk of it.
- First-Episode Twist: Chara lives.
- Friend Versus Lover: Asriel and Prase do not like each other, primarily because they met when Asriel's relationship with Chara was turning toxic. While they've somewhat patched things up, Chara will still spend time with Prase when they need some space from Asriel.
- Fuzz Therapy: When Chara gets spooked by Endogeny, they'll calm down by petting the dog amalgam.
- Good Parents: Most of the families in the Underground, as a deliberate contrast to the Abusive Parents most of the fallen humans had.
- Gratuitous Costume Description: Asriel lovingly describes his elaborate formalwear on several occasions.
- Grow Old with Me: Chara angsts about not being able to have this with Asriel.
- Handicapped Badass: As a result of the buttercup poisoning, Chara's mobility is somewhat limited, but this doesn't stop them from learning how to fight and eventually becoming Asriel's official honor guard. Solidified in under my skin, there will be flowers, where they successfully duel Holly (who is ready to kill if she has to) to a standstill.
- Happily Adopted: Chara, by Asgore and Toriel, and later Frisk, by Asriel and Chara.
- Happily Married: Asriel and Chara after the events of you in your veil and your pale white dress, and Asgore and Toriel throughout the series.
- Harsher in Hindsight: Chapter 8 of we light ourselves up from the deepest of pits consists largely of Chara spending time with their family and cryptically musing about Moses. It's mostly adorable on a first reading, and the air of wistfulness underlying the chapter can be explained away as the fact that the Barrier will probably break soon, changing everyone's lives forever. Then it's revealed that Chara was planning to kill themself all along, and was spending their last day with their loved ones.
- Heroic Suicide: Chara frames the poisoning in someone else's fire as this: if Asriel takes their soul, he can go to the surface, gather six more souls, and break the Barrier. Subverted in that Chara actually is suicidal, they're just making the plan to break the Barrier as a way to justify their death to both Asriel and themself, and also in that Asriel ends up stopping them at the last moment.
- Honor Before Reason: Holly's general MO.
- Interspecies Romance: Asriel and Chara.
- Jewish and Nerdy: Chara is very quick-witted and enjoys reading. Liron is undoubtedly the most scholarly of the fallen humans (ze isn't Jewish, but has some Israeli heritage).
- MayflyDecember Romance: One of Chara's objections to marrying Asriel is that they'll continue to grow old while he stays young forever. It doesn't end up stopping them.
- Modest Royalty: All the Dreemurs, and later Chara.
- Morton's Fork: Chara tries to put Asriel in one in we light ourselves up from the deepest of pits to force him to allow them to commit suicide: either let them die or take their soul. He manages to Take a Third Option and talk them down.
- Named by the Adaptation: The six souls in canon (Patience, Bravery, Integrity, Perseverance, Kindness, and Justice) are given the names Prase, Rufus, Innig, Liron, Astis, and Holly, respectively.
- Near-Death Experience: Chara is sickly, has been suicidal on multiple occasions, and is in a fairly risky line of work (monarch's personal bodyguard), so they have a lot of these. Every time they survive one, they get more white in their hair.
- Not Blood Siblings: Downplayed. Chara was raised by Asriel's family, but considers Asgore and Toriel too loving to think of as parents, since their blood parents were abusive.
- Official Couple: Asriel and Chara.
- One Head Taller: Many, many heads taller. Asriel being a Boss Monster helps.
- Our Souls Are Different: Just like the original game, they're heart-shaped, with colors depending on the owner's species and personality, and it's sometimes possible to absorb the soul of a recently-deceased member of a different species. The person doing the absorbing gains great strength, while the person who got absorbed becomes a voice in the head of the person who took them. In the series, it's also stated that souls can be temporarily severed from their owners without killing them, allowing for feats of magic only possible with the power of multiple souls, but if the soul remains severed for too long, its owner will die.
- Parental Abandonment: Frisk was abandoned on the mountain.
- Plot Driving Secret: Chara's illness being the result of poisoning themself is this for someone else's fire. Asriel ends up telling the secret and saving them.
- Prematurely Grey-Haired: Chara. According to Word of God, every time they have a near-death experience they get significantly more white in their hair. By the end of the last story, Chara is forty years old, and their hair is almost completely white.
- Rapid Aging: Justified. Chara never completely recovers from the buttercup poisoning, so they can't stand up to the years very well.
- Resurrection Sickness: Something similar happens to Chara in we light ourselves up from the deepest of pits. While they don't actually die, they spend long enough with their soul almost completely severed from their body that they nearly die, and when they finally return to their body, they wake up weak, white-haired, and overcome with emotion.
- Say Your Prayers: When Chara is about to attempt suicide in we light ourselves up from the deepest of pits, they say a Hebrew prayer that's traditionally used as last words. Subverted in that they survive.
- Self-Harm: Chara struggles with this for the entire series.
- Sexy Discretion Shot:
- After Chara and Asriel become adults, their relationship starts becoming physical, and from then on some scenes end with a fade to black when things get heated between them. Averted in the side stories live inside a green moment and seal our lips until we're found, which show the act in detail.
- Liron/Astis and Rufus/Innig get scenes like this in we light ourselves up from the deepest of pits.
- Sharing a Body: The fallen humans (except Frisk) temporarily sever their souls at the end of we light ourselves up from the deepest of pits so Asriel can absorb them and break the Barrier. While severed and held by Asriel, the souls act as voices in his head. He can read their memories, but risks getting lost in them if he tries this. The souls can even have conversations with each other in Asriel's mind. Astis and Chara end up cracking a bunch of dirty jokes, much to Holly's chagrin.
- Shout-Out: Among others, Chara and Prase are established to be fans of Homestuck, and the novel Kitchen by Banana Yoshimotonote is shown to be one of Chara's favorite books.
- Simple, yet Opulent: Chara favors this style (most notable in their wedding dress), in contrast to Asriel's preference for the Ermine Cape Effect.
- Spared by the Adaptation: Chara and Asriel, due to Chara surviving the buttercup poisoning and Asriel thus never absorbing their soul and getting attacked by humans, as well as the owners of the six human souls, due to Asgore never declaring war on humans in this timeline.
- Suicide Is Painless: Averted in someone else's fire. Chara poisons themself and spends weeks in agony before Asriel decides their Heroic Suicide scheme isn't worth it and has his parents heal them. Later in the series it's also revealed that Chara climbed the mountain to kill themself, and survived the fall with serious injuries. Played (mostly) straight in we light ourselves up from the deepest of pits, though. It's never stated clearly, but permanently severing one's soul would probably be relatively painless, since souls can't feel physical pain, only emotional pain, and even a temporary severing almost completely disconnects the body and soul. Chara tries to kill themself this way in the last chapter, but Asriel talks them down.
- Talking Down the Suicidal: Asriel to Chara in someone else's fire and again in we light ourselves up from the deepest of pits.
- Team Mom: A male example in Astis, appropriately enough for the soul of Kindness.
- The Last Dance: Chapter 8 of we light ourselves up from the deepest of pits is supposed to be this for Chara. Subverted in that they end up surviving.
- Theme Naming: All six of the other children are given five-letter names that relate to the concept of joy, to match Chara and Frisk's names.
- There Are No Therapists: Mental health works very differently for humans and monsters, so there aren't any human psychiatrists in the Underground.
- The Woobie: All the fallen humans have traces of this, but especially Chara.
- Troubled Fetal Position: Chara spends a good deal of under my skin, there will be flowers curled up in a chair.
- Warrior Prince: All the royals can fight. Asgore and Chara wield the royal trident, while Toriel and Asriel use magic.
- What's Up, King Dude?: The Dreemurs all make a point of being very available to their subjects, and don't like to pull rank. MK even addresses Asgore as "dude" in we light ourselves up from the deepest of pits.
- You Are a Credit to Your Race: Played more positively than most examples. The only humans Chara can stand are the other fallen.