How to disable ability?

[Foxiu]

Hello, I'm creating ability which transfer HP from caster to target and from target to caster but I have a problem,
I want to somehow disable ability (make it something like passive (unclickable)) if caster have less than 15% HP.
How can I do that? Is there any option in trigger to "disable/able" ability?

 

[Raven0]

Well there is an enable/disable ability action under 'player' in the action menu. But I think what you want to do is remove the ability (under unit actions) and then replace it with a passive dummy ability that doesn't do anything and has the same icon.

Either way you'd have to run periodic checks on the units hp to know when it's below 15%.