ball lightning question and projectile number.

Hi. I have a question...
if I increase the projectile number of ball lightning. does it mean the damage going to be doubled?
or only one line of ball effects at one time?

for example.
if there are a line of 6 projectiles and there is a monster in the middle.
do all of 6 projectiles damage the moster? or only one among 6 ????

so confusing..
help me plz

One one projectile per cast can damage an enemy, same as other skills. However, multiple balls from different casts can still damage the same target.

so you mean... 26% less damage greater multi project can damage more than single projectile ball lightning?