Persevere.
Make you you don't interact with the crux itself while it's in your menu.
It only gives you one option, and if you press that button, it will already be too late to stop yourself once you realize it was dismantle.
... which I am sure I don't know from personal experience. ...
Just beat hard mode Crota. That's it. Having Eidolon Ally or a Husk doesn't improve your chance so don't listen to the people that say it does. I had 2 drop for me the 2nd week of Hard Mode without all these so called requirements people are telling you.
I beat crota 11 times with no crux.
Then did this:
1. Have Edillon Ally Equipped
2. Have Glowhoo Equipped
3. Have Any Hard Mode Guns/Armor Equipped.
4. Have Titles, Ship, Sparrow.. Equipped.
Got it first try.
No tips or tricks needed. You have a % chance to get it after beating it initially and getting glowhoo. Dont matter what u equip could be second tey could be 50.
1 Go outside at night
2 Pray to the stars that you want the crux.
3 Do a "blood" ritual
4 Look in the mirror and tell yourself you will get crux
5 play hard crota using lfg members
6 fail hard crota because no one was doing their jobs
7 cry
8 come to the forums and ask how to get it again
9 get told to do another series of events and do those only to fail getting the crux again