Main character of the series is Rosette, a young nun in the Order of Magdalena. The Order specialises in exorcisms. Exorcisms with 'holy bullets', sacred barriers, vials of holy water and special armor piercing bullets laced with spells.
Rosette has a partner, the demon Chrno. Chrno has lost his horns and thus can not tap into the 'life energy'. He has made a contract with Rosette: she supplies him with life energy, and he helps her in her quest. Most of the time he maintains a human form (which consumes less energy) but when he has to go all-out, the clock-pendant that Rosette wears is unsealed. While Chrno assumes his true (demonic) form and dukes it out with whatever nasty is threatening Rosette, the clock runs backwards like crazy...
Rosette's brother, Joshua, has special powers. He has been abducted by Aion, a high-ranking demon with nefarious plans. Aion's group is called 'The Sinners', and Chrno was part of his group before he defected.
The plot is, of course, of how Rosette searches for her brother and battles Aion and his minions -- aided by Chrno. When Aion took Joshua, he gave him Chrno's horns, giving Joshua fearsome powers that he uses to tear down the orphanage where he and Rosette lived. The people living there are 'frozen' in time, and the whole site is contained by the Order of Magdalena after which Rosette and Chrno join them.
Aion is gathering the seven 'apostles' around him: people who have received certain powers from God, to be used for his own nefarious plans. In the end it turns out that it wasn't Joshua, but Rosette who was his target. He merely needs the apostles to 'awaken' her, and use her holy powers to sow various disasters on Earth.
The cast of characters is certainly likable: the lively Rosette, the cautious Chrno, the innocent Azmaria and the stubborn Satella. The series also begins quite action-packed, but as the series progresses and the main plot starts, it starts to lag. The quality of the storytelling of the individual episodes is quite uneven as well: one episode may greatly advance the plot, while the next episode is filled with non-related goofiness. That was a bit of a letdown.
Also, the fanservice focussing on nuns is... something different, to say the least.
- Great animation;
- Interesting plot.
- Ending is not really satisfying;
- Plot isn't moved along smoothly;
- Lots of shouting. It's in the plot, all right -- but it is a bit tiresome to have whole episodes with certain characters never saying a single thing in a normal tone of voice.
I'll give it a 6.5.