This is a paid asset, but now you can download Fireball Prefabs Free.
Detail this asset from Unity Store: Original Link
Fireball Prefabs v1.3.1 (Latest version)
“If possible, please buy the package to support the developer”
• Fireball explosion
• Highly customizable, easily create new effects by altering existing prefabs
• 5x fireball prefabs
• Added Mobile Shuriken versions
Unity 2019(+) compatible
Support available for assistance if any problems should occur.