nightghosts drop one ever 1.2k-4k kills. Lure them in the Dark Green map by hitting them one time climb the ropes and move from where you lured them at the start at the left corcer of the small map until you retrace youself back there and tank them all until they all die without leaving any one of them out of average of how much hp one hit attacks for when you hit-lured them to the left where you can see the drops b/c sometimes the maps are the ones that don't let you loot properly and the stuff gets stuck to the ground and disappear before you pick one steely up out of 2k-3k average kills regular drop.
I would suggest just buying cheaper stars until you can farm wolf spiders for hwabis, get a big spider familiar too. I got a set of 12 pretty easily during a 2x event. edit: JK thought this was reboot probably harder on regular servers LOL