Making a unit attack all adjustant units with chain lightning

[Interceptor]

Heya, I've got a very complicated task. I need to make a unit attacking all adjustant enemies around it, firing a chain lightning at each one and every chain lightning must bounce 4 times (i.e. hit the 1st target and then another 4) with 10% damage reduction per hit.
Basically, a barrage that fires chain lightnings.
Any ideas how to do it?
*I prefer JASS, though GUI can be also fine if I try to JASS-ify it.

If your suggestion works, you shall earn a well-deserved reputation from me.

STOP!!!
Don't offer me things like "give an ability chain lightning and make it autocasting when an enemy approaches, blablabla" or "create dummy units that cast chain lightning". This thing is NOT what I need and is NOT effective because it doesn't offer variable damage + the dummy units won't know which unit to zap with the lightning. Doing so is a waste of both mine and your time.

 

[Anachron]

So what you are searching is a Chain-Lightning system triggered?
if not post an image to clearify what you need.

 

[Interceptor]

Instead of normal attacks, the special unit (O) fires chain lightnings
The 1st attack hits all the targets, bouncing at the nearest unit.
The 2nd attack hits the 2nd target and continues by the nearest and so on. Notice that the furthest target is unaffected, since it's too far.
The 3rd attack hits only 3 units, same reason.
The 4th attack hits 4 units.
The 5th attack hits all the 5 units.

All the mentioned attacks happen simulatiously (at the same time).
I repeat, this is not a spell, but a normal attack.

 

[The_Silent]

An very easy way would be to use the ''Item Black Orb'' abillity.

 

[Anachron]

I see its makeable but requires effective coding and.. no headache ofcourse =/ I have one.

 

[Interceptor]

An very easy way would be to use the ''Item Black Orb'' abillity.

What the... ?
Explain more, please?

 

[The_Silent]

What the... ?
Explain more, please?

It may not be exactly what your are loking for, but it allows the unit to cast a spell instead of attacking, when it declares attack. Check it out yourself you're still interrested.

 

[Interceptor]

I checked it. Not what I need, because it will make the unit fire only one chain lightning at the same time.

 

[Anachron]

Interceptor its exactly what you need. Then you make an trigger, check for the ability being cast, create dummy units which have chain lightning and then order them to use it.
Its pretty simple.

 

[Interceptor]

In that case the damage won't vary but I guess I'll swallow it.
Silent, Anachron... you earned your rep.

[Solved]

 

[Anachron]

Why isn't damage changed? Just set the level of the chain lightnings of the dummys. The orb chain effect does 0 dmg. Make sure dummys cast on the target of the ability being cast. HF