Lightning is one of the easiest Sector Effectors to create. It of course
is only available with the Plutonium Pak, so if you're running the 1.3
version, you'll need to upgrade. It's worth it, believe me.
Start out making your sector, a single big one will suffice here. Insert
two Sector Effectors, and change their lotags to 28.
Insert 8 NaturalLightning sprites (tile #4890), four to each SE-28.
You can have more than four per SE-28, I'm keeping it small for now.
Place them in a circle fashion around the SE-28. For one group of SE-28
and lightning bolts, change all of their hitags to 1. For
the other group, change all of their hitags to 2. When the
lightning "strikes", it will randomly jump to the positions of the matching
lightning bolts you placed.