Witch Hex - nature of the Will saves

My question specifically touches on the "Misfortune" hex but could apply to others as well.

Party was up against "Helmed Horrors" (constructs with an Intelligence score). Normally constructs are immune to "mind" effects. Our Witch casts a "Misfortune" hex on one to subject it to a 50% failure on most actions. The Hex gives a Will save to avoid the effect.

Would you rule that Misfortune "bends" reality around the target so that it is not a "mind" effect despite the Will save? Or, would you rule the misfortune is all in the mind and therefore could not affect constructs? If you would rule that since the constructs had an INT score they could be affected, how would you rule on non-intelligent constructs?

My ruling on the fly:

If the misfortune hex had some language like, "...is a mind-affecting effect," then the construct would be immune to it. (See the charm hex for an example.)

Just because something requires a Will save does not make it mind effecting. Sure most Will saves are but some arnt.

Cure wounds spells used on Undead require a Will save but are not mind effecting.

The Slow Spell requires a Will save but isnt mind effecting.

The witch hexes indicate which of them are mind-affecting. Evil Eye and Charm, for example, contain the sentence "This is a mind-affecting charm effect." Slumber does not have that sentence, but is specifically references a spell that is mind-affecting.

I would describe Misfortune like you did above. The witch is bending reality...altering the victims fate...something like that.