I building a Summoner who's Eidolon has the feat Final Embrace Horror. Anyone damaged by his grapple is shaken. I'm also giving him an amulet of mighty fists with the Cruel enhancement, which makes shaken enemies sickened when struck. Would both these abilities trigger after the first constriction? Or would I have to hit him again?
Grappling isn't an "unarmed attacks or natural weapon" as far as I know, so it wouldn't benefit from any enhancement to the Amulet of Mighty Fists.