A neat - and nasty - weapon to incorporate into your adventures, it comes with a new weapon property: Everdeath. This includes soul-drinking on the part of the weapon, and makes it extremely difficult to resurrect anyone killed by it.
The backstory provided includes fragments of a journal that could be used as clues in a search for one of these weapons, as well as a temple-full of fanatics the most notable of whom are issued these blades. See someone with one of those, it's advisable to run... unless you are brave, powerful and lucky!
To look at, a Daemonwatch Blade is a greatsword with irregular serrations and spikes ornamented with a stone that looks like a reptilian eye. Finding a scabbard for the thing is likely to be difficult! As well as the Everdeath property, it is also capable of tracking the last person hit with it, so even if you flee after being injured you may not get away...
As well as all this detail, plus a big drawing and full stats, you also get two item cards. One has all the details as given here, the other is blank so if you like the sword but want to play around with the properties a bit, you have scope to do so.