Bludgeoning Angel Dokuro-Chan Ripiru

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. However, one angel, Dokuro-chan, decides to try to change the future without killing him. The problem is that Dokuro is very temperamental, and is constantly killing Sakura (along with many others) in incredibly bloody ways with her giant spiked club. Good thing she can bring people back to life… if only to gruesomely kill them again the next time she loses her temper.

Bokusatsu Tenshi Dokuro-chan tells the story of a 13-year-old junior high schooler, Sakura Kusakabe, who, twenty years in the future, while attempting to create a "Pedophile's World" forces all women to stop aging after the age of twelve, offends God by the side effect of having created immortality. Dokuro Mitsukai, a member of an order of assassin angels that are called Rurutie, has been sent from the future to kill him. Believing that Sakura can be redeemed, Dokuro decides instead to keep Sakura so occupied that he can never develop the immortality technology. Due to her impulsive nature and super-human strength, however, she frequently kills him with her gigantic spiked kanabō (club), Excaliborg, on a moment's impulse, but returns him to life moments later with angelic power. Sabato, another assassin of the Rurutie order who uses her feminine wiles to do her job, is dispatched to complete Dokuro's original mission: Sakura's assassination. (Source: Wikipedia)