The idea is good and the start isn't bad, but it needs work.
Atm it looks like a smudge fest, blurry, lacking definition and dynamism.
Those fire limbs and ice "shapes" are tiny and barely visible.
The fire has lost its color, it's kinda monotone and motionless.
This is a bolt, a missile of fire and ice that strikes, not moving like a jellyfish. Try to show it in ur icon(u could draw some speedlines).
So, i suggest u to create some well defined shapes, keeping in mind that ur object is moving fast, not floating.
Also, try to make the transition between fire and ice more visible and use more color variations.
Apheraz gave u some advices aswell. So, if u consider our suggestions and practice a little, there might come out a good icon.
Note: The smudge tool can give good results(in some cases), if it's used wisely and not exaggerated.