SC2Mapster

I'm trying to create an ability that when clicked (or the hotkey is pressed) it instantly applies a permanent (I remove it with triggers) behavior on the caster.

Basically, how do I create an ability that targets the caster automatically and applies a behavior?

I would look at something like stim, etc, but this is such a simple skill that I'm bound to have tons of extra fluff if I try without asking you guys.

Look at the Stimpact ability, remove the costs & use a behaviour with a duration of -1

If you need a more detailed explanation, ask again

/€: Just took a look at it, because of the duration (it seems either 0 or -1 is fine))
So you need an ability of type "effect - instant", an effect of type "apply behavior" and your behavior

Well, as I said, I will end up with a lot of extra fluff that way. I'm trying to use the "ability - behaviors" field to apply the behavior, and I think it is working. The skill is targeting the caster and everything (thank god for defaults). Now the issue is that the button for the ability disappears after I use it once. How do I keep it there?

Well, I guess I will do that. I just don't get why a behavior ability (ability of type behavior) makes the button disappear after being used...

Edit: Done as you say and it works. I guess behavior abilities are meant for toggling.