Uniqueness
My assumption is that these are intentional, but just in case:
Magic Items: Nest-of-Snakes (Pyorra 49.10 and Faroe 09.28), The Witness (Albann 23.05 and Faroe 46.07)
NPCs: Birger (both in 09.09 Guthram), Cyr (both in 11.25 Norbast), Eilian (10.11 and 11.11), Ljot (43.03 and 45.08), Mari (06.19 and 13.13), Yisharu (34.18 and 46.15 - couldn't figure out what Ariadnh had against a random villager!)