Lightning beam that cause death

I'm making a RPG map and is currently making the mechanics for the final boss, but I have a problem:

I want the boss to go to the center of a region then make 6 beams from him to 6 other regions around the main region, and if a unit cross these beams, it dies. I don't know if this can even be done with wc3 editor.
I know how to make the lightning effects and activating the triggers, all I need help with is the "crossing beam = instant death" effect.

This thread should be of use to you.