I fail to see your point. Surely there is something better here than just a mindless torturer who got offed in a riot.
Like, say, for example; His cruel and often overly excessive punishment drove him to torture people in their own homes, until word of his victims reached the ears of the local royalty. Fearing for their lives the nobles organized a prison riot and in the midst of the chaos, had the despicable jailor hung from the rafters with the very chains they feared. Unaware of the consequence that would reemerge.
Threw that together in like 15 seconds, so clearly this isn't that hard.
Still the same thing but more detail as to why/how it happened. I crave the details of his demise.