Maybe something that might add some punch is tweaking the timing of the animation itself. Not sure if its because of my bad internet but the sword swing seems to be a bit slow. Speeding up (or slowing down) things might make the whole effect more punchy and emphasize more on the beats.
I think something that might also help is adding a few more emitters on the build up and impact, just so it matches the dramatism/intensity of the ground part. Maybe the sword could be absorving something during the build up as if it was powering up, or emitting some flames. The same goes for the impact, with the textures you have you can easily make some nice shaders for impact/burst particles. Adding some refraction might help too.
Hope this helps for future things, very nice materials you have! Thanks for the breakdown.