#vessel construct

Do I think Cas will cut out his grace by the end of the show (since he can’t switch species and will always be an angel technically)?

Yes, but not til the last episode.

I also think that the show has spent a great deal of time making this to not be as big a deal as it would have been, say, in season 6. Angels have been depowered (in general) as a species a LOT. They can really only heal (to a reduced degree) and pick info out of people’s heads these days. I’m not even sure if they can smite anymore? Maybe only on an individual basis they can but certainly not in a “shield your eyes” and wipe out a whole room basis anymore. They can’t fly. Cas can easily be physically hit unlike in S4 when Dean tried to do this and nearly broke his hand. Like, even if he keeps his grace then still the strategic “useful” aspects of having grace are pretty few and far between (lbr) compared to what I think Cas would see as the benefits of opting to remove it by choice when the time comes (for real).

The main thing grace does (that the show focuses on like in 9x11 and 14x01 for example) for Cas these days is it effects how intensely Cas feels emotions and how he eats/drinks. I think the only reason Cas currently wants it is to shield himself from feeling the full force of his depression. Aside from this Cas remarks on the effects of having grace in mostly a negative or matter of fact way. “Coffee doesn’t effect me.” I think when Cas weighs the pros and cons (and once his depression is truly addressed and actively fought against), that there’s more pros by far to just getting rid of it at this point. He only keeps it to use as a tool for his family for what little benefits it has these days. It’s little more than a well worn pocket knife at this point. The show has framed it this way for Cas for a while tbh, including in episodes Dabb has penned himself, which is a greater indicator imo of the character’s trajectory.

Cas certainly didn’t think twice about giving it up to save Jack, pros and cons be damned. The decision, thus, is already technically been made, the show imo is just waiting for the most dramatic opportunity for Cas to cut it out. Cas not only values humanity objectively, he values it personally, for himself. Back in S10 when Cas was talking to Hannah about angels feeling emotions he spoke painfully, but honestly about how there’s bad things, but also good ones. As much as I absolutely HATE Carver era in retrospect (understatement), it admittedly did some good things with aligning Cas towards an organic and satisfactory endgame as an angel who chooses to completely let go of what he was built to do in order to pursue what he loves and finds value in: humanity.

You’re not a bother at all, anon,  Simply, one involves a soul and one does not. Metaphysically, the two are nothing alike.  One functions on only EMF, while the other functions on damaged EMF plus a soul.  In both cases the soul is “blocked” (or in the case of soullessness, absent) so they are similar in this regard.  For both, the ability to give a fuck is essentially gone, so the narrative can treat them as equals in many ways (which is why we got the foreshadowing mirrors in 9x17 IMO). Additionally, there’s degrees of “humanity” involved in being a demon, shades that are achieved by injecting “fixes” to the damaged EMF.  There is no equivalent to this for soullessness since there’s no damage to EMF and the soul can not be broken into pieces for a humanity “infusion”.  It’s black or white, no shades of grey.

Nope.  I haven't wrote anything like this (and it honestly makes no sense to me) nor have I seen it on my dash.  All my meta for grace and angelic construct is tagged: "grace in the machine".

No angel will ever be 100% human.  When angels say they are "human" they are saying they no longer have grace.  It's actually not the same thing.  When grace is removed from their angelic construct one of two things will happen: 

If they are unvesseled their angelic construct (including their soul) will fall to Earth (taking the appearance of a meteor) and impregnate someone (this is what happened to Anna).

If they have a vessel their angelic construct will become "permafused" with their host's cells, taking on mass (whether the host's soul is ejected at this point or functions alongside their own is something that I feel the canon will never address, though I suspect both souls stay in one body, drawing on "the machine's", the meatsuit's, resources resulting in a shorter lifespan: think boiling water at double the temperature).

Grace, uncontrolled by an angel, burns through humans.  This is how humans burn their eyes out at the unvesseled sight of them.  They are in the "radiation" zone and die from exposure.  Humans can not handle grace without an angelic construct to channel it.  The only exceptions to this may be vessels (the pre-programmed kind) like Dean and Sam.  There is something in the construct of their meatsuit that is specially "fitted" to receive an angelic construct overlay: think wires for a home stereo system without the system yet.  Now, in theory, these wires are already built to handle the flow of grace so grace could be "forced wired" in without the system (the angel) ever being installed.  

Okay, so we knew that the premiere was going to have to address what was going to happen to the unvesseled angels right? These angels are grace-infused wavelengths incapable of being "reborn" while their grace is intact. As Hael said, most of them are just circling the atmosphere, looking for vessels. And Hael's vessel?

After less than a day it was immediately showing signs of grace decay on the flesh, the result on an imperfect resonance with the host's soul and flesh. Is this likely because teenagers can not give informed consent? The only time we've seen a child consent to being possessed is with Jimmy's daughter Claire.

It is worth noting that Claire most likely prayed to help her father. Prayer and will (desire of the heart/soul) are both important parts of the ability of a host to give an angel informed consent to possession.

Ezekiel's possession of Sam is different. It is not binding we are told. Sam had to embrace the will to live in his heart (his soul) in order for Ezekiel to use that as a means of healing him through angelic possession, and in doing so heal himself.

This is not true consent. It is parasitic symbiosis. It is codependency, a bond of either life or death.  Despite this, we are told Ezekiel can easily be expelled through Sam's will alone, due to the nature of the harmony of their shared resonance. It would appear that archangel vessels are a good fit for lesser angels, universal donor blood as it were.

In both cases of consent a verbal "Yes" is the only requirement shared. One's soul must produce this manifestation of will through a sound wave in order to accept the celestial one.

This is the song of resonance, the key that unlocks the door to physical possession. There are some vessels that can make this bond with different angels, much like temporarily arranging a set of picks and picking a lock, this likely requires significant concentration on the angel's part as it is not a "true" key, a true resonance by design.

Sam's archangel vessel is able to be "picked" like this, as is Jimmy Novak's. The Novak line presents a particularly durable vessel line that has managed to hold millions of souls at once, which is not an easy feat by any stretch of the imagination. The monster soul decay from the souls of Purgatory took weeks to ravage Cas' vessel though the effects could be seen almost immediately.

This is also the case with Hael's vessel. To fix this, Hael intends to claim Cas' skin for herself. This possibility alone suggests further that Cas has a soul required to make informed consent and that he is alone in his skin. During 9x01 Hael makes no mention of the soul of Jimmy Novak, nor does any trace of him appear to remain (though I've argued this for some time). This may be something more angels want of Cas. It's too early to tell.