Building controled by A.I. casts custom spell only when attacked, how to change this?

[Insanewarlock]

The title pretty much says it. I want the building to cast the ability whenever possible instead of casting it only when it's attacked. The building has no attacks of its own enabled if this matters. Any ideas why this is so?

 

[Accname]

The AI behavior for spells is hardcoded, it depends on the spell you used as a base. There is not much you can do except to change it to another spell or to trigger it entirely. The faerie fire spell usually works okay. The standard AI will cast faerie fire whenever possible except on the caster itself, it will never auto-cast on self no matter what.
You could experiment with some of the other spells too, I never tried all of them to see if one of them can be used in such a way.

 

[Insanewarlock]

I used finger of death, it works fine.