Enya the Hag controls Justice, a terrifying stand that is made of a cloud of fog. It can control anybody by tying strings of fog into their open wounds. Since it is a fog, it is also basically impervious to physical attacks. Justice was ultimately defeated when Jotaro uses Star Platinum’s agility and power to disperse Justice before it can reform itself.
Correction
Um actually … Jotaro did not disperse Justice. He used Star Platinum to inhale Justice, causing Enya to suffocate.
Um actually star platinum sucksd enya off so hard she collapsed and died on the spot