So, when you go below the Temple of Berath in Neketaka and kill the boss, you get a quest item that says it is an estoc that cannot be removed from its scabbard. Any idea what to do with it? It didn't come with a quest, and when I brought it to the smith I didn't get a dialogue option to reforge it or anything.

I haven't done that yet, but that sword is cursed according to the quest and I wouldn't be surprised if you had to complete the quest to be able to use it, or even not be able to use it at all if you kill the boss for it, as you didn't earn it.

I would try to do the questline for it and see what happens.

What quest are you talking about? I didn't get a quest associated with the sword. 

 

I did complete the quest that sent me down there, the one from the high priest of berath.