Im currently 45 and completing black spirit quests. Im stuck on a quest where youre supposed to extract a basteer black stone from a basteer weapon, altough it doesnt say that exactly. I extracted the stone from the weapon, yet te quest still exists. Ive read you can use ultimate styd weapons, but i cannot figure how to get them from the market place as thyre stuck in preorder. Ive even gone to the extent of levelling another character to the same mission and sharing the weapon and black stone fron tht character, which when i extracted the stone, also didnt effect the quest. 

Do you have talk with Grandbill?

https://bddatabase.net/us/npc/43433/1/

Take a look at Item Exchange List