Love the style.

Thank you so much for your criticism, I'm a begginer when it comes to drawing, specially doing animations, I'll try to improve based on your points.

This isn't bad, but it could be so much better if he really twisted his hips and shoulders more. Now he's almost just using his legs and arms. And the flame should have much more inertia, so it doesn't flip back and forth so quickly. I also think the arm that isn't attacking should be doing a sort of opposite motion of the attack, to create more momentum in the swing.