The best way to think about Oryx, in my opinion, is to think Greek. In the beginning there was chaos, the void, from which came many powerful beings. To name 3 Alpha Lupi (the Traveler) Oryx and the Darkness. Possibly also the Nine, but I doubt that. From this I believe she reproduced asexually by using the Hive magics and her own blood. Yes, I said she and her, I'll touch on that after. She first created her initial spawn, the only one we know for sure is Crota, but other likely members include Xol Yul Ur and Eir. Now back to the she. As shown in the rusted lands grimoire, the wizards are actually the superior beings in the Hive. They also lead the use of magics which would, as I suggest, be necessary to reproduce.