:O GASP!!!

OH NOES!!!
SOMETHING HAPPENED!!!!!

hmmm..

I'll try and help you with your action on this one, purely as a critic. Since this is an action scene, the viewer shouldn't care about the background much. First panel is the best, particles are great, as well as the limp form, but the tail that's smacking the baddy doesn't look like it's in much motion.

For every other panel, experiment with abstract backgrounds. Panel 2 could use either erratic lines or radiating lines to emphasize the roar, panel 3 would look good with some parallel lines of varying thicknesses to show speed, for panel 6 and 7 I'd get some parallel lines and cut them off at the horizon, and make more exagerated impacts throughout. Panel 8 is strong, but it'd be pwerful if the baddy was wincing and his hair was blowing back. ETC. Read some manga or superhero comix to get an idea of what I'm talking about.