For creating lightning effects you need at first 2 locistion, where effect begins and where it ends.
Lightning - Create a Chain Lightning - Primary lightning effect from source Point1 to target Point2
Remember to remove location leaks latter.
If you want to link lightning effect with dummies, create a loop that while creating 18 dummies, sets Point2 to position of last created unit (since I'm sure Point1 is constnt in cause of unit who summons whole effect), creates ligthning effect, and removes location leak.
Unit - Create 1 Lightning_Dummy for (Owner of LC_Caster[LC_Index2]) at (LC_TargetPoint[LC_Index2] offset by 400.00 towards ((Real((Integer A))) x (360.00 / 18.00)) degrees) facing LC_TargetPoint[LC_Index2]
Set LC_Dummy2[LC_Index2] = (Last created unit)
Unit Group - Add LC_Dummy2[LC_Index2] to LC_Group2[LC_Index2]
Unit - Add a 8.00 second Generic expiration timer to (Last created unit)
Set LC_DummyPoint[LC_Index2] = (Position of LC_Dummy[LC_Index2])
Set LC_UnitPoint[LC_Index2] = (Position of LC_Dummy2[LC_Index2])
Lightning - Create a Chain Lightning - Primary lightning effect from source LC_DummyPoint[LC_Index2] to target LC_UnitPoint[LC_Index2]
Set LC_LightningEffect[LC_Index2] = (Last created lightning effect)