In the very beginning of KH Sora was using a wooden sword & he couldn't hit heartless, but in KH 365/2 days when Xion couldn't use her keyblade Roxas lent his to her & used a stick, now how come he could hit heartless?
Roxas has a special power then sora because sora is a boy. Roxas on the other hand is a nobody. He has a special power because he is a nobody. That is why.
Ты will only be able to get that anser from square-enix the last one was wrong becaus in kingdom hearts hollow бастион sora was able to hit the heartless with his wolden sord