why did the reoncarnated majin buu, uub need training from 悟空 if he almost killed Goku?

悟空 not training uub 更多 like they train together uub the only person beside vegeta that can give 悟空 a good fight

He didn't almost die he just wasn't in his super saiyan form.

Uub needed help just unlocking his full potential and using his destructive power at will and controlling it at his whim

because he is a good guy now and 更多 clearly is because 悟空 is the pure-hearted saiyan

because his power did not get use to the new body yet