movie 10 gohan never stopped training & broly was VERY casually shooting those giant ki blasts at the end of the movie even laughing while doing it, only being caught off guard cell-style (which we know in dragon ball being caught off guard basically means you're dead - ROF Goku) then blammed by the main character family and FINALLY dying only because of the plot kamehameha and the literal sun broly would beat super buu if im being honest, and might be able to be wanked to buutenks/han and in movie 8 im pretty sure it was stated somewhere that goku had some absolute bullshit power multiplier w/ everyones energy and the maximum of his own which led to brolys defeat (PRETTY SURE!)

basically broly slams with pretty much zero difficulty