Angela looks like a little girl but is an immortal who longs to die so her soul can reach the afterlife. Her partner is Meg, a 17 year old Anglican nun who has holes in her memory. Angela is very close to Meg and says that she can live only as long as Meg needs her.
Together, they belong to a mysterious organization whose mission it is to hunt demons: creatures that possess humans as well as prey on both humanity's corruption and innocence. What sacrifices will be called upon humanity for this war? Can this war against the demons even be won?
- Always Chaotic Evil: Demons, most of which are barely sentient and hunger for ether. They possess humans and consume their souls just so they can have a material body to continue their hunt more efficiently by eating living flesh directly.
- Ambiguous Ending: It's never made clear whether Meg and Angela and survive though the ending seems to indicate that at least the world wasn't destroyed.
- Anyone Can Die: The only main characters who (might have) survived are Meg and Angela.
- As the Good Book Says...: Meg recites Bible quotes to cast spells.
- Body Horror: Actually doable due to Healing Factor. Angela is unarmed. What do you mean unarmed? She chopped it off to use as a weapon. Yes, she uses a removed rib as a weapon once.
- Bury Your Gays: Inverted as Meg and Angela are the only named cast members to end the story alive.
- Christianity Is Catholic: Averted in that the series acknowledges Meg and Angela work for an organization within the Church of England, and that the Anglicans and the Vatican aren't particularly close. The casual reader could be forgiven for forgetting this, though, given that the Anglican Church has a lot of Catholic trappings left over even today, and the series plays them up.
- Church Militant: Meg and Angela. An army later turns up to quarantine the town that the demons ravaged though all they end up doing is mopping up the demons after the heroes end up taking the Big Bad out.
- Cursed with Awesome: Angela's curse leaves her immortal, regenerating, and with no soul/ether. It makes her the perfect demon-slayer, and immune to possession.
- Deal with the Devil: Meg's dad allowed himself to be possessed to save his daughter.
- Emotionless Girl: Angela. After centuries of life plagued by countless horrors, it's the only way not to go mad.
- Functional Magic: Rule Magic - all magic, no matter the tradition, is powered by "ether," which only living souls possess and demons desire.
- Heroic Sacrifice:Detective Edward, Trude, Gertrude and Hisami to kill Gilles de Rais's subordinates.
- Historical Domain Character: Lord Gilles de Rais (Bluebeard) and Joan of Arc.
- Improbably Female Cast: A total of two male characters with a significant amount of speaking lines and only one who is named.
- Life Energy: "Ether," which powers magic and which demons love to consume. It's basically soul energy, and only living beings have it. If a person loses all their ether, they will die. Demons like to possess ether-rich people with low defenses, consuming their souls and taking over their bodies. Those bodies are then twisted and warped into nightmarish forms so the demons can consume living flesh from which to drain ether directly. Part of Angela's curse that makes her an effective demon-slayer is that, despite still being alive, she has no ether to lose.
- Love Makes You Evil: Gilles de Rais who was driven mad by his love for Jeanne d'Arc.
- Meaningful Name: The demon-slaying scythe AGLA, which is (according to Bonus Material) actually a Kabbalistic acronym for a phrase praising God ("Athah Gabor Leolam Adonai" - "Thou art powerful and eternal, Lord") and thus a powerful word by which to banish and control demons.
- Nice Job Breaking It, Hero!: The main characters practically enable the villains plans by bringing Anathema to the seal thus breaking it. To make things worse, the villains couldn't actually touch Anathema.
- Not So Different: Angela and Gilles de Rais in that they will do anything for their love.
- Public Domain Artifact: Angela's second scythe turns out to contain a nail from the crucification of Christ.
- Really 700 Years Old: Angela who's been around since the 1400s after Gilles de Rais took her soul. She's also the one who founded the demon-hunting order within the Anglican Church, and isn't just their weapon.
- Religion Is Magic: Meg uses religion to focus and channel her magic.
- Stuff Blowing Up: Detective Edward's primary weapon is gunpowder.
- Witch Hunt: Nepalese villagers organized one of these kill Meg's dad in her backstory after he became a demon with the standard Torches and Pitchforks. Not that it actually achieved anything.