My Husk dropped after 67 attempts over a few days (close to the same for The Taniks Cloak now). So it might take a while. To lessen the grind of the Eidolon Ally run The Chamber of Night and get to the point where the Cursed Thrall keep spawning. They spawn every 6 seconds and when you cause a group explosion they all count towards your kills. To get Crux you just need to jiggle RNG's fun bits.