When can I get specific blueprints?
Solution 1:
Having all pieces of Retribution set but one, all previous sets completed and even quite a few pieces from later sets, I defeated final boss and advanced to NG+.
Once there, I started getting worried: I already got almost whole Slayer set, but still couldn't find the last piece of Retribution set.
But now I finally got the last piece of Retribution set from Botis in Maya.
My guess is, the quote from Wikia is outright wrong.