Wedding Rings of Death

The Wedding Ring is an artifact used by the Pillar Men to plant a highly potent venom inside a human. The purpose of the ring was to ensure that anyone who promised to challenge the Pillar Men at a later time would have to do so, lest they die a horrible death. In Part 2, Wamuu and Esidisi used these rings to prevent Joseph Joestar from escaping his fight with them 33 days after their first encounter.

About
These rings have some sort of timed action since the venom won't activate until the needed time passes. The ability from the Pillar Men to pass through human bodies without damaging them allows them to place the rings on different organs. The only way to neutralize the poison is to kill the Pillar Man to which the ring belongs to and drink the antidote found in each of their nose rings, appropriately referencing the phrase, "Till death do us apart." Because the poison is different in each ring, one can not use the antidote from one Pillar man's nose ring on the poison from another Pillar Man's wedding ring.

Trivia

 * Esidisi asks Kars if he wanted to place a wedding ring on Joseph, implying Kars is in possession of one as well.
 * Apparently, it was common that Wamuu use this trick on others.