A 40+ Bst can solo this drop (at the rate of 2 kills per 2 hours lol, a bst uses their 2hr ability to kill these IT mobs). So if you have a bst friend who wouldn't mind devoting the time to you, you can ask for some help. Otherwise you can do what I did - and that's lvl bst up to 40 yourself so you can just go and get your own.
That might seem like a drastic measure just to get one item, but having bst at 40 is extremely useful in any case, especially for BCNMs (there are some BCNMs 20 and 40 which are extremely bst friendly and even bst-soloable). PLus lvling bst is really fun, I rather enjoyed it :)
So just thought I'd throw that out there as another option for getting this, if getting a subligar raiding group together is a real pain.
In fact I got the Virgo Subligar 1/1 when I killed the Fomor Ranger for fun while trying to solo the Fomor Beastmaster for my BRD's Gaudy Harness :) Pretty useless to me seeing as my rng is lvl1 and my cor isn't even unlocked. OH WELL.
Good luck!!