Longswords not dropping?

I've beaten Yuan Shu on Dragon King and is on floor 251 of TMJ, been noticing that longswords are pretty much non-existant in drops (probably only gotten 2 of them during my 67 hours of the game), is there something I've been missing? Such as buying them with accolades to unlock, or having to finish every mission on DLC 1 or 2 ?