Bokusatsu Tenshi Dokuro-chan

Bludgeoning Angel Dokuro-Chan (Japanese: 撲殺天使ドクロちゃん, Hepburn: Bokusatsu Tenshi Dokuro-chan) is a Japanese light novel series written by Masaki Okayu and illustrated by Torishimo. It centers on a teenage boy and a killer angel from the future who constantly gets him into trouble and kills him violently and repeatedly, often removing his head with her spiked club named "Excaliborg", only to resurrect him seconds later. The novels were first serialized in the Dengeki hp magazine published by MediaWorks. Later, a manga version was created, written and illustrated by Mitsuna Ouse serialized in Dengeki Comic Gao!. Finally, an anime version was adapted and aired in Japan between March and September 2005. A second anime series aired between August and November 2007. In late 2005, a PlayStation 2 game titled Game ni Natta yo! Dokuro-chan: Kenkō Shindan Daisakusen was released in Japan.

Plot
In the future, a man named Sakura is destined to create the technology for eternal life, which (due to Sakura's lolicon tendencies) freezes all women's aging once they turn twelve. God refuses to allow this, so he sends his angels to the past to kill Sakura before he can do this. But one angel, Dokuro-chan, decides to try to change the future without killing him. Problem is, Dokuro is very temperamental, and is constantly killing Sakura (and lots of other people too) in incredibly bloody ways with her giant spiked club. Good thing she can bring people back to life - if only to grusomely kill them again the next time she loses her temper.

Why it Rocks
Cool animation.

Great stories.

Awesome characters especially Dokuro herself.