Custom Abilities???

Ok i've looked everywhere and I still can't find this subject of matter...

I want to create my OWN SPELL! You know, like the ones that ARENT in wc3 originally? Like the Kamehameha or a spiral of ice that damages, or even an ice storm that damages and slows enemies...

What I mean is...I love the spells that people make freehand, and are INCREDIBLY unique. How do I go about making my own Spiral-of-flames? is it just some epic triggering? please point me in the right direction

No, you haven't. Have you looked in the Trigger Editor?

Yes. Depending on what you want your 'custom skill' to do, it can vary from a very brief amount of code to 100+ lines of code. If you're just starting out, I recommend reading tutorials about triggering and such.