a collision detection system would be (hard i know) great! When the tornado collides with an entity, we could add an ent_create that creates roof parts turn around the tornado but not going to the center of the twister, so it moves away, and dissapear.
Also , a kind of big dust cloud on the ground would be nice.
Oh, and sound

I can provide a sound, i'll post back with it
Thanks, god #2

(xXxGuitar is the 1st)