unless you can magically access the source code of the game and check for the possible drops, your only option would be trial and error until you get it, or wait for them to update the list. question is, why would you need 2x largeswords? they only add dmg in PVE and they also make you 10% slower (plus no block or flip), so using them would be quite inefficient IMO (you can slash twice with a normal sword if youre good enough in the time it takes you to slash once with a largesword, and there are good PVE swords..)
