How does the apprehending fusion

[C4M3R0N]

So upon rereading the fusion I'm not entirely sure how it works and was wondering if anyone had an idea and could clarify.
Apprehending from Archives
My question pertains specifically to the last part "Additionally, the target must succeed at a Fortitude saving throw (DC = 10 + half the weapon’s item level + the ability score modifier you apply to attack rolls with the weapon) or be unable to cast spells or spell-like abilities for 1 round."
This part of the ability only applies in conjunction with when you use your reaction to prompt the trip attempt, correct? That's initially how I read it and how I've thought it was played. But on rereading I'm not entirely sure. Does it actually apply to every hit with the weapon? That seems stronger than intended so I'm leaning towards it functions with the trip.

[Pantshandshake]

I would think the trip attempt and the binding of spell use happen in conjunction, and you don't force a save on every hit.

[Eric Clingenpeel]

Its all one ability that can only be used once until you rest to regain stamina. Its not every hit.

[BigNorseWolf]

When you hit someone, you hit a little toggle on the gun as a reaction and it zaps them extra hard.

You then get a free trip attempt (which to me reads as a new trip attempt not not using the previous attack roll at a trip attempt) and regardless of the results the target makes a fort save or they can't cast spells/use spell like abilities.

[C4M3R0N]

Alright great. So it works like I originally thought. Thanks!