you could edit the buffs/effects so that instead of stars that fall down its a blizzard stick. Note:animation used in blizard is a single projectile and in the blizzard spell you customize how many fall. While modifying starfall you cannot customize the amount of projectials simotaniously fallen on a target.
Change starfall (target) to Blizzard without the (Caster)
adding a cold armor (target) buff will also make it look cooler
and it would be advised to remove the Starfall (effect) aka the light with moons and stars in it that appears above casting unit.
instead have no effect or maybe a cloud effect would like nice.
And if you want this to be a really sweet abillity you could use GUI
Event
- Generic unit event - A unit starts the effect of an abillity
Condition
- Abillity Comparision - Abillity being casted is equal to (your starfall)
Action
- Hero Create Item for unit - Create item (a made up item with a fan of knives spell but make this also a blizzard projectile using same method) and give item to triggering unit
- Hero Use Item - Order Triggering unit to use item carried by hero = to (made up item) on target point of abillity being casted.
- Hero Drop item from hero - Drop (made up item) from triggering unit
- Item Remove - Remove last droped item
That will make it look cool
hope I helped
Edit: Oh crap you just posted what you actually wanted sorry
Well heres the way to fix your problem.
Event
- Unit starts the effect of an abillity
Condition
- Abillity beging casted = to (A blizzard with starfall icon and stuff that has no blissard buffs effects or damages besides aoe)
Action
- Special effect - Create Special effect Starfall at overhead, falling on unit(s) targeted by abillity being casted
- Wait .50 seconds
- General - If condition then action else
+Condition
- spell (the modified blizzard) is level 1
+Then
- Unit Damage area - Cause trigering unit to deal 50 damage to Poinnt of abillity being casted in a 250 by 250 area
- Special effect - Create Special effect Starfall at overhead, falling on unit(s) targeted by abillity being casted
- Wait .50 seconds
- Unit Damage area - Cause trigering unit to deal 50 damage to Poinnt of abillity being casted in a 250 by 250 area
and so on for as many waves as wanted
+Else
- If condition then action else
+Condition- spell (the modified blizzard) is level 2
+Then
- Unit Damage area - Cause trigering unit to deal 100 damage to Poinnt of abillity being casted in a 250 by 250 area
+Else
- If condition then action else
+Condition
Well you get the jist if needed contact me for more help
Hope this heled