what will win?
it depends on what rasengan if its the rasehshuriken then it will obliterate the chidori but normall rasengan then i would still say the rasengan becuase in one episode sasuke and naruo were fighting and kakashi stop them from connecting with chidori and rasengan they hit into a tank and u can see that the rasengan did more damage than the chidori
@jax: a chidori is a messed up rasengan. When monatomic told kakashi to try to mix lightning chakra with rasengan he horribly failed. He created a ball of lightning chakra that completely lost any spin that it had from rasengan. So you tell me what's better, a lightning sphere or a sphere of violently spinning chakra.
Rasengan > chidori