Dark Arrow --> Triggers & Spell Editing

Alright, for a campaign I'm planning on making I need to be able to have the original Dark Arrow. It was the Half-Elven Ranger's Ultimate spell, and Stunned the target unit, reduced its HP to 1, and left it in "stasis" through the stun, as in it coulnd't be "revived" or killed :ggani: . I was thinking about doing it based off Envenomed Weapons with a different icon, but I'm not sure how it'd work. I haven't done much in the Wolrd Editor, but here my idea:
Once the spell is cast on the unit, it is "poisoned" with 20HP loss/sec until at 1 HP and use triggers to stun the unit, make in spell immune, and invulnerable. However, I'm not sure how to do that (I don't have a lot of free time) and I don't know if the invulerability will cancel the -20HP/sec. Any sugestions/ideas?

base it on storm hammer, change missle art to arrow, when spoell castron unit, set unit hp to 1

This is kinda hard to do. Like the dude above said, base it on storm hammer, make it stun for a duration you want, then comes the trigger part.

event
-hero uses a skill

condition
-the skill used is dark arrow

actions
-set darkarrowunit = targeted unit
-for a = 1 to 20 do
for b = 1 to 4 do
if darkarrowunit's hp >=6 then
darkarrowunit's hitpoint - 5
wait for 0.25 second



hope this works. Or if you mean to set the target's armor to invunerable then you can do it the same way, just add the line "make target unit invurnerable" at the beginning and then turn it off after the loop(which is 20secnds later)

actually i'm not really sure if this works ;p

Thanx, I'll try it later tonight. In the descriptions I've seen of Black Arrow, it says that the target is permenently stunned, but I don't know if its possible to make the stun permenent and dispellable.:bgrun: If their is, then I'll mess around with the trigger and see if I can get if to work. Thanx again.