Redshift Community

After defeating the final boss ( THE UNNAMED ) in "Sunken Monastery" , he has a chance to drop a certain item called "Warded key", with nothing in its tooltip , it's pretty hard to find a use for this item , perhaps some of you quest gurus can help me find a use for this item , as I expect a powerful boss to drop a useful item, which does not seem to be the case here. Thanks in advance

EDIT: Thanks for the help.

That boss drops random items, and you can fight him again after 7 days pass (just make sure you don't visit the Sunken Monastery until then).
That key is for breaking into some houses in Mithria.

It can unlock some houses in cities, similar to the skeleton key, and doing so will still be considered a crime, despite not actually "picking" the lock.