Unleashing my destiel omegaverse headcanons draft (alpha!Cas and omega!Dean).
In my mind, in omegaverse, angels would be genderless in the same way they are in canon. They have no primary or secondary gender.
When Cas possesses Jimmy, he “adopts” his secondary gender (now, I personally don’t think Jimmy gives off alpha vibes, but let’s say he is for the sake of this post). As an angel, Cas can suppress the urges that come with being an alpha. He is utterly indifferent to any sort of urges he should be feeling, and to prejudice or roles he “should” be fulfilling as an alpha. For example, he acknowledges Dean’s scent, maybe even finds it intriguing, but that’s all he does. He is aware of secondary genders and how they function, but only in theory. He also doesn’t act as an alpha “should” to Dean (read: stereotypically), doesn’t expect Dean to perform any “omega” roles, basically just treats him like his secondary gender doesn’t exist. Whenever Dean is in heat, I think he’d just offer to zap it away with his grace like an inconvenience (Dean is very grateful to be able to go back to functioning normally, but is also disappointed Cas didn’t help him the old-fashioned way. Not that he’d admit that :) ).
Now, this changes when Cas loses his grace and becomes human. Suddenly, he’s faced with having to deal with being an alpha. He finds every smell overwhelming, has no idea how to manage his ruts, or even how to recognize them in himself. This is when, as he is faced with Dean, he truly becomes aware that Dean is an omega. And he smells truly wonderful. Cas then proceeds to exhibit insane force of will in holding himself together, because he doesn’t want to hurt Dean. Perhaps he runs to Sam in a panic, begging for him to help him manage his urges before he does something he regrets. All in all, his time as a human is truly miserable with the added difficulty of his gender.
Cas is insanely relieved to get his grace back and finally be able to subdue his hormones. Except he finds that, even though, physically, his body is not going crazy anymore, he can no longer ignore Dean’s gender the way he used to be able to. He realizes he had been subconsciously pushing down his physical attraction, even before he became human. What he thought was simple intrigue of Dean’s gender and scent, was in reality a repressed want. And now that it’s been shoved in Cas’ face in a way he could not ignore, he can no longer trick himself into thinking Dean’s scent does not matter to him.
Cas gains an entirely new view of Dean, and of secondary gender in general. I think this is the moment he truly starts to identify himself as an alpha, instead of simply genderless.
Also adding my omega!Jimmy thoughts here. Look that man is an omega in my eyes, no way he’s an alpha. Maybe Cas keeps his omega status for season 4-5, because that’s Jimmy’s gender, but once Jimmy is gone, without him noticing, his body starts to adapt to his own identity? Angels can literally repair dead bodies, I don’t think it’s out of the realm of possibility for Cas’ vessel to start shifting internally to reflect him better. But since angels generally don’t go around in soulless vessels, he never considers the possibility that he is not the same as Jimmy was. I’m just saying he’s in for a big surprise when he loses his grace :)
