You mean using Locust Swarm? I wasn't sure if it would work right. If it doesn't, then just create a meteor at a random point in a region centered around the caster.
I have tried and it works fine except of one thing: The Meteor (locust) always lands the same place. Not on the map but like ((position of triggering unit offset by xx)).
i dont see the pointi makeing this spell as all you need is like a starfall and change the effects of it, though i havnt tried (this isnt my comp mines down at moment), i dont see the point, if someone cold poinnt it out for me.
1) You can get rid of the casters by adding an expiration timer. This will reduce the triggers. 2) If you make a unit with the meteor model, negative life regeneration, and AoE Damage Upon Death, you can reduce the actions in your triggers. 3) You might also be able to summon the unit via the Locust Swarm ability, making the spell a normal spell.