Recently I played a game with the goal of taking the Nazgul in Dol Guldur's ring. So I worked my way through the Diplomat Tree to unlock the Buy Artifact Claim interaction, only to discover that the Ring was not able to be targeted. Anyone know of any other method to get my hands on a Ring of Power?

Lore Bit: I think it would be possible in-lore for someone to use one of the Nine Rings safely. They'd obviously have to be strong enough to take it from a Nazgul, and being robbed of their ring would probably hurt that Nazgul a lot, but Sauron was only able to bend the Nine to his will because he had the One, so as long as the one remains lost, it shouldn't be too lore-breaking for someone to wrest control of one of the Nine Rings.