It took out two pain bodies. rasen shuriken destroys things at a molecular level. It was big enough for Jiraiya to put multiple holes in a row of buildings rasengan>Chidori which is just a copy of it. The reason why it hasn't killed anyone is cause of plot but it is not a fodder jutsutitle says it all. Rasengan has yet to kill any one in this series. It seems to almost be at the level of troll = to Amaterasu. Thus rasengan is a jutsu that kills no one. How can a rasengan users beat any one?