Good question! And one that I grappled with a while back.
In essence, removing Sam’s soul from his body won’t cause his body to grow back. If it did, we’d have dead borrowers popping back to normal size all the time!
Essentially, the curse needs to be stripped from the host soul in order for them to return back to their normal size. Otherwise it leaves an imprint on the body it left behind and small they stay. This is something that Celeste, and only Celeste, knows how to do, and she’s certainly not about to just casually go break her own curse. She’s the only one able to tamper with her own archangel Grace that’s been intertwinned with the borrower souls.
Well, Rowena is often drawn to power, so I can see her seeking out Celeste if she gets wind of what she’s up to.
Unfortunately, Celeste disdains actual witches, as useful as she finds their powers. Though she might be interested to know Rowena is able to use magic without demon interference, she’s already met witches like that in the past. She won’t let Rowena come close to her plans, and Rowena would spurn this treatment.
Queue them becoming worst enemies and Rowena working to upset Celeste’s plans, especially if it helps her learn a few angelic secrets.
After a forced relocation from Trails West, new information surfaces about the witch the brothers have sought for years, throwing them all into a confrontation they weren’t prepared for, and could never have expected.
Characters:Sam Winchester, Dean Winchester, Bobby Singer, John Winchester, Walt Watch, Bela Talbot, Rufus Turner, Celeste, Castiel
The first hint that Celeste wasn’t all that she seemed to be came from her name, in the very first story!
Celeste: Celestial, heavenly.
Further hints were found in her character profile for anyone who looked close enough:
She has no quantifiable age, created before humanity was born as the angel Saraqael. Though her host, Celeste, is a human, the one controlling her actions was never mortal.
The gender of Celeste is purely dependent on her chosen host. As a multidimensional wavelength of celestial intent, gender is meaningless.
In past millenia, she has taken male forms and so Saraqael is often associated with a male angel, though this could be no further from the truth. If given enough time in a host, however, she does tend to take on the mannerisms of that gender, like most angels.
Saraqael : Prince of God. The Fallen Watcher.
One of the seven archangels of heaven originally trusted to lead the heavenly host. One could call her current vessel an ironic twist, as she lusted for the daughters of men. Her primordial powers of protection have been twisted and corrupted, and she seeks to free her fallen brother by any means necessary.
This desire to break Lucifer of his cage is what brought her to Azazel’s notice originally, and he brought her under his control, an aspect of their relationship that chafed at her, though she put the demons he tasked to her to good use.
With Azazel out of the way, she can expand her influence without fear of retribution from the remaining Princes of Hell.
She has taken the time to learn true witchcraft since falling, discovering that it was an excellent substitute for her own celestial powers when she needed to avoid the notice of the angels tasked to seek her out and bring her to justice.
Brothers Apart 