Giving frost nova a projectile art?

Is there anyway to make spells like Frost Nova, which are instant on target, have a projectile that flies to the target?

Or perhaps, some kind of missle spell, like firebolt, that does aoe damage to it's target?

At Frost Nova you can change the model of the effect, but it won't be like a projectile I think.
You can also change the Projectile Art of some spells.

There are, basically, two ways to do this. The first way is the simple way:

Add the "sphere" ability to the unit. The sphere ability changes the unit's missile art, creates an optional attachment art (of which 1 is removed each time the unit fires) and gives ALL of the unit's abilities a missile art. This is usually how we give the blink spell a model art.

The other way is to use a dummy ability and spawn a dummy unit that fires an AoE projectile. I prefer this way as it gives you more flexibility with effects you can create with the AoE explosion (for example you can give the dummy AoE firing unit a modified burning oil ability for some really wicked sfx)

Additionally, it should be noted that giving the unit a Sphere ability will make it use the sphere spell projectile for all of its spells. This can be worked around by making a trigger that removes the sphere ability whenever a spell other than your Frost Nova is cast, but it's a little risky, if you ask me.

OR you could make frost nova based on storm bolt and change its projectile art and set stun to 0 and set buff to Frosted. Then in triggers, simply create a dummy unit that frost novas the unit with buff Frosted. I might be wrong but th15's second response might mess up if the unit moves out of the way cause then he will get hurt but the sfx wont show it.

Changing Storm bolt to 0 stun is a no no. That will make the spell stun whoever the target is for ever. Your best bet is to use 1 of the 2 ideas th15 gave you.

Another point to note with Storm Bolt (and ANY other stunning spell) is that it will interupt channeling, even if the stun durration is not noticable. This could have severe balance issues in certain gametypes and is of particular anoyance with Inferno because it removes some of the spells usefulness for spell triggering (although the new (relativly) and improved channel can replace most of it trigger spell uses)

Dummy units can have homing missiles enabled just like spells. They really give you a lot more flexibility in terms of what effects and SFX an attack can have. The downside is that using dummy units generates a whole load of "extra" units and abilities (a caster unit, the original dummy spell, the dummy unit's actual effect spell and any SFX abilities) and can cause your object editor to get hopelessly cluttered if you don't arrange your units properly.