So I've done a bit more work on this. I've given the core a bit more intensity and added in some mesh data for some whispy bits off the core. I've also reworked the sparkles coming out of the trail to give it more energy. I couldn't decide whether it'd look better having the trail expand over time to make it look like it was dissipating or whether to have the trail shrink over time to fade away so I did both. The first video is having the trail expand over time and the second video is where it shrinks.
I still feel like my work lacks energy and that visual 'punch' that FX should have. Also looking at it the smoke textures look popcorny.