How can I edit the Frost Nova to missile spell?

I want to create a spell called "Fire Ball" but I am not sure how to make a fire bolt fly.

Also, why doesn't EarthQuake hurt units when I change it to hurt Organic units.

And I how do I make normal spells into hero spells?

first you can only make spells based off another. so u gotta find sumthin taht fits what u want and change the graphics Earthquake is hardcoded so it wont hurt units unless u make em building type. And if u want to make unit to hero spells copy the unit spell and change to data to like a hero spell.