I think something that makes this animation feel less impactful, which I've also notice in some of your other animations, is that your animations feel very sequential.
Basically, it seems to me like all the actions your characters perform are right behind each other, not often are there two or more things happening at the same time. Here I see it like this:
1.First Pan starts floating
2.His arms and legs go into position
3.He slams to the ground
4.dust clouds rise up
5.The fire effect happens
6.He screams(also very sequential on its own, his head goes up and then he opens his mouth)
Especially not allowing to happen 3, 4 and 5 is really jarring to me, and even only allowing these things to happen at the same time would heavily improve the animation imo.
In all your animations I can see you're very dedicated to them and put your all into all of them, but I think they would be improved a ton if animations were less sequential.
I hope this helps a bit!
Edit:
Now that I've seen the reference material, I understand why you made certain parts of the animation sequential like that, whoops :p.
However, I still think that in general trying to make the animations less sequential might improve them a lot