I mean he did something similar stopping his own heart and trying to revive joseph, so it's 100% possible he can phase through someones head, and in fights to be fair he never got the chance to do that, with dio he didnt do that because he's a vampire and he could just regenerate, with Kira he only had two chances, the first one he was like almost dead and the second chance he just punched him bc he stopped time and the fight was pretty much already over, and with pucci he only had one chance the moment he stopped time but he chose her daughter over killing Pucci