How do I beat Characters in Ultimate Ninja Heroes?

I need help on Naruto : Ultimate Ninja Heroes on PSP, I can%26#039;t deafeat any characters in Legendary Sannin hard level I kept powering up my Characters but it can%26#039;t work what do I do ?|||You should first train in normal or easy level. Then when you can defeat them you should now try hard level. For guides and tips check www.gamefaq.com