Modding Help Sword spawn projectiles on hit. (Like Star Cleaver)

Hello! I am a big fun of old broadswords that can spawn projectiles on swing. So I was editing my broadswords when I suddenly thought: if we have fire1, fire2... to edit, can we write something like these: "fire1": { 'there is projectile spawn script'} ? So I am really want to add Star Cleaver. Please help me!

 

I don't know if you could simply just add such a thing... however, there is a way to make your own version of traveling swoosh and edit it to spawn your own projectiles. However, that's tied to a alt ability and not primary.

 

I can do it as reversed traildash but I want to make it as prim ability.