"You know humans don't live in this world anymore, Nee-chan. They only survive."
- — Ryuuko Matoi
In what should have been a final battle, something went awry, leaving Satsuki and Ryuuko now drift through a dangerous world, battling a bleak reality to keep their grasp on a tenuous purpose. Their story of life after catastrophe, and rebellion against fate's design, unfolds there at the end of days.
Tropes for At the End of Days:
- After the End: Not so much after any more than it is during, as Ryuuko mentions the time before, while crazy, was normal.
- Anyone Can Die: Even Mako
- Apocalypse Anarchy: Yes, as Ryuuko and Satsuki can go about pillaging and swiping supplies without any consequences.
- Bad Future: If the above quote above didn't clue you.
- Biblical Motifs: This is more overt with the title
- Big Sister Instinct: Satsuki is very protective of Ryuuko, clearly. The inverse also occurs for Ryuuko.
- Bittersweet Ending: Chapter 28 and the epilogue, where Ryuuko sacrifices herself to save the world and Satsuki, leaving the latter alone. Satsuki goes on to live, later on having a daughter and a niece, before later dying of old age and being reunited with her sister in the afterlife
- Body Horror: The life-fiber clusters when they devour a person, also that bit with with Nui
- Dark Fic: Obviously. Like Ragyou said, getting rid of her wouldn't stop the life-fibers, instead, they've gone haywire.
- Death Fic: Most of everyone that Satsuki and Ryuuko knew are dead and that includes Mako, Iori, and three of the Elite Four
- Good Thing You Can Heal: Ryuuko, by means of being a Half-Human Hybrid. If she wasn't, she'd be dead already.
- Heroic Sacrifice: As we find out, Nonon's death. Houka wishes she had died protecting Satsuki instead
- Ryuuko's death
- Ill Girl: Satsuki in one chapter when she comes down with a fever, leaving Ryuuko to protect and find medicine for her.
- Last of His Kind: Houka as we find out in one chapter, is the last of the Elite Four, as Nonon died protecting him
- Leeroy Jenkins: Ryuuko almost always charges into battle without a plan.
- No Periods, Period: Discussed in flashback three years prior, when Satsuki asks when will Ryuuko's next cycle begin. The conversation is awkward, really.
- Rape as Backstory: Satsuki, true to canon.
- Red Oni, Blue Oni: Satsuki and Ryuuko, true to canon. Satsuki is more collected than Ryuuko, while Ryuuko is hotblooded as usual.
- Smart People Speak the Queen's English: Not quiet a British accent, however, Satsuki, having a more profound vocabulary than Ryuuko, talks in a rather posh manner.
- Sibling Incest / Situational Sexuality: Actually, the fic was really platonic up until about nine chapters since the beginning but, since there are no others around until a certain point and Ryuuko has needs. Satsuki, while implied to be compliant, wasn't very comfortable with it at first, however, she mostly goes by Ryuuko's signals, which is to say, if Ryuuko is fine with it, so is she.
- Sliding Scale of Idealism vs. Cynicism: More on the cynical side, considering what happened.
- Verbal Tic: Satsuki referring to Ryuuko as "You child" or, when she was briefly annoyed, "You brat"