Werebane slows or stops the HP regeneration of monsters it hits. (Most monsters regenerate HP pretty slowly, but it could be nice on ones that regenerate 1 HP per turn.)

Werebane confers extrinsic protection from shape changers when wielded.

Change Werebane’s base item to a ring of protection from shape changers. Confer the same sort of properties as it currently has now: while wearing the ring, you will deal double damage to and possibly even sear werecreatures even if your weapon is not silver, and possibly even instakill them on a critical hit.

Werebane provides protection from shape changers and immunity to lycanthropy while wielded.