Tip: when using impact frames, impact frames look a little messed up when following the animation smoothly, to fix this, try to make the actual animation (apart from impact frames) fall atleast 1 second and a half after the impact frames (meaning you wanna make it go I to the future a little)
you shouldve drawn his skull literally friggin cracking from the blow man. like, fist makes impact, skull goes KKRRKKKK (my impression of bone breaking noises) in slo mo, and then bro goes flying.
what fps do you use, and i must say the impact frames were great, although you should add some after effects like debris and maybe adding slow mo for a buildup? amazing animation