Is that why minato said his tech is incomplete?Well kakashi learnt rasengan and failed to combine his nature with it. So he developed chidori. Obvously chidori is a superior jutsu otherwise kakashi would have continued using rasengan. Chidori is therefore stronger than rasengan. People can say what they like logic dictates chidori to be superior.
Also to combine shape and nature is harder than just form manipulation.
Chidori without a doubt
Rasengan - Chakra
Chidori - Chakra + Raiton
yes that is the reason rasengan is no match for chidori which is a combo of both far surpassing rasengan when complete like rasen shuriken then it s far stronger.Is that why minato said his tech is incomplete?