Since this is for your demo reel, I would personally go expensive on the particles.
If it were an in-game effect and you had a particular budget then I think this would probably be ok.
So here’s my critique for what it’s worth.
Your main fireball is bright and lacks structure (the head of the fireball)
The first thing I do when I start to do an effect that I either haven’t done before… or I want to see what others have done for a good start is to go on youtube, here, or just do an image search.
If it were me, my fireball head would look something like this:
Now this is obviously from a fluid sim, but it has structure… an inside, and outside… dark, light.
My main head would probably be a sphere with a material. The sphere shouldn’t be “perfect” so give it some deformation, but that would be my head.
From that head (sphere) I would emit my trails.
Your fire trail looks to me like it’s a single texture that is speed stretched (I could be wrong about that but that’s what it appears to be) I would do a fluid sim of a fireball with a fast death rate so your really only have a “ball” not a ball with trail (as seen above)
I would use that as a basis for my trail.
That will give you some movement with a flipbook texture that you currently don’t have. It would also eliminate the “sharp” edges that are occurring right now.
I would do the same with the smoke… have a fluid sim flip book of smoke and run that as your smoke.
Your trail also looks a little thin behind the head. Basically your head and your trail look a little separate.
But using a sphere might help that gap. The sphere can also be elongated to help the gap… just have to play around with it.
Also… have WAY more embers. This thing is firey and should be dangerous. Look up a video with just a simple camp fire and you’ll see more embers than you have here.
My philosophy on FX is go friggin crazy on your first attempt. You can always scale back… but if you start smaller it’s harder to get that initial image out of your head.
Also add a light to your fireball… and if you’re going to have it hit the sphere you’re going to need a nice firey explosion to go along with it… with hot debris… black debris… part of the sphere could break and fall to the ground. etc.
Oh also… might play with the thickness of the smoke. One of the cool things about fireballs is there’s no “right” way to do it. So you can have a heavy black smoke trail that might be a nice contrast to the fire… and also have the trail maybe start earlier so you have fire and smoke mingled together… just play with it.
Good luck man 