Farming boss drops//general question

[Adachi452]

Hey everyone, this may be a moot question at this point. But im trying to get the Darklight Greatsword from Amdapor Keep...i keep getting every other weapon except that one, whether im in a team or solo....V_V

No way to boost the drop rate of a specific item at all is there? Im guessing no...but i thought i'd check.