The Jailers are an organization with the purpose of stopping the escape of Tharizdun. While their intentions are arguably good, as the release of Tharizdun could mean both a multi-planar war as well as the end of the entire multiverse, their methods more often than not range from questionable to downright awful. While they don't worship a particular deity, the Jailers of the End can possibly be described as a counter-cult, combating the cults of Tharizdun, whether they know they are worshiping Tharizdun or not. While their exact founding date isn't known, the Jailers of the End seem to have existed since at least the Great Wasting in some form.
The organization seems to be set on collecting Illiadian divine artifacts for one reason or another, being convinced that they're the key to stop Tharizdun from escaping his prison. Seemingly, they may be part of a ritual to reforge Tharizdun's chains.