Multishot spell - problem with penetrating arrows

i've made a trigger which creates arrows as units with locust at a target location
with angles. it moves the arrows by 6 towards the point and detects a nearby enemy and damages it when reaching distance of 30 checking every 0.01 sec, it works but the problem comes when i want the arrows to go through the target, it damages it like 5 times and kills it! wtf?

thats becouse you check the distance every 0.01 second, maybe you can mess some with the Unit Comes Within Range event, that will only happen once to the unit uncluded with some special conditions.

Perhaps you could achieve the same effect without using triggers, just give the arrow the pheonix fire ability with modified range and graphics, making the duration time long (so it only strikes a unit once) and cooldown very short (so it hits all units it moves past).

Do your arrows have collision? Maybe they're crashing into the unit and cannot go through them.

Also, why not use carrion swarm? Unless the unit is meant to home onto a certain location and not move straight.

Unless you want the unit to move really fast (projectile speed) BUT vanish upon hitting a target, at which point you could give the unit kaboom (goblin sapper) and have its aquisition range really low so it explodes at any unit it acquires (while you trigger move it).

they have locust so the collision doesnt matter
they dont crash into the unit, they go through, but damage a few times
maybe it is what ondizz said, since its checking every 0.01 seconds, the arrow might still be near the unit on the 0.02 second, and the 0.03, etc, until passing away

im kinda confused, about the phoenix fire you suggested..
i dont think that will work
im using certain angles and the arrows kills themselves when colliding with a unit
until now, that i want them to penetrate for example MAX two units..
i need some condition advices here :/

add a custom value to the target unit when the arrow first hits it, make a condition so the arrow won't damage the unit if it's custom value is equal to the value you added to it.

yes but then ill have to set the custom value of it to 0 when the spell is ended and the trigger forgets who the picked unit is by the end of it..
but you gave me a good idea, ill put them all in a group and remove the group on the end..