How would you..

Make an AOE Invisibility skill with triggers? I know its possible with jass, but is it possible with just triggers now?

E: Unit - Unit begins casting an ability
C: Ability being cast equal to DUMMYSPELL
A: Unit Group - Pick every unit in (Region centered at (Target point of issued order) with size (400,400) and do ( ____ )

I know one way of doing it is to create a wisp with Invisibility (range 99999) in some corner for each unit in the region, and order it to cast invis on each unit in the region, but I don't know how to do this.

But preferrably, I'd want a mass windwalk for the backstab damage, but I'm really not sure how to do that.

And to clarify, what action would create a region at wherever the mouse is, because I guess you can make a region at the targeted unit using the above action, region around the caster using (Position of (Triggering unit)), but what about just any spot on the ground?

If you want to do Windwalk, you could give all your units a Windwalk-esque ability, and disable it (so it doesn't appear on any of them).
Then, when the spell (probably a blizzard clone, I'm guessing) is cast, detect all units that are affected by it, see if they belong to that player or are allied to him, and then enable the ability and tell each of them to use it. Then disable it again.

This is hypothesis, as I've never made more than two trigger-based spells in my life. But if you want Windwalk, I think this is the way to go.

The disabled windwalk may mess up if they have some other windwalk-like spell. And some of my heroes use up all 7 slots, so I guess I'll just stick with an invis or something. But I'm still not sure how to do that.. any suggestions?

How do you make an art effect stay on a unit while its in effect. The bear claw from roar or lightning cloud from unholy frenzy stay overhead while the spell is in effect. (Art - Effect doesn't seem to work)

This could be done before w/o JASS, just base it of infernal and then pick all units within range of 600 of (summoned unit) or something. However, I dunno if a you can trigger a spell silmuntaniously with one unit even if the cooldown and mana cost lies at 0.

http://www.wc3campaigns.com/forums/s...t=invisibility

I remember I made A trigger version of the spell