A stylized fireball based on the one seen in the game King of Meat, I used this trailer as a reference - https://www.youtube.com/watch?v=ehBAn64695o
Built in Unreal Engine 4, I used the fireball in the trailer above as a reference when drawing the spark/flame textures for use in the effect.
Effect in Unreal Engine 4.
The explosion uses a large flame/burst particle and smoke along with rings that have a dissolving material applied.
The fireball trail uses three particle emitters with different textures which were made in Krita. Each emitter has slightly different behaviours in lifespan/noise/velocity to add some variation.
The sparks use similar behaviour to the ember emitters. The smoke has a higher vertical velocity force.
The main head of the fireball uses a single particle that generates a death event to activate the explosion emitters.