Increasing time dammage

[GrandMaitre]

Hi everyone,quick question :
I changed the flamestrike model to a kind of dark beam.
But the beam animation is longer than the original flamestrake's animation.
So how do I increase the time of the dammage dealt?
Cause currently it stops dealing dammage after 3sec.

 

[DaneTheBeast]

For flame strike "Duration - hero" controls the main flame and "duration - normal" controls the small fire that stays afterwards

 

[GrandMaitre]

thanks