This probably won’t be interesting to anyone else, but I just wanted to write this out because Richard’s acting choices here are beautiful.
The raise of the shoulders right at the start is indicative of Gabriel making himself appear bigger. He sees the threat, and initially, he tries to intimidate it. That, to me, is also Richard taking into mind the idea of wings, with the raise reflective of the wings flexing outwards, again into this larger, intimidating state.
This plays into the idea that the acting choice is reflective of instinct, as Gabriel falls back into the role of archangel. It’s something he’s denied for so long, and in the lift of the shoulders, we also see the metaphorical lift of his various personas. He’s using his identity and status as a weapon here.
Also notice how he turns round, he constantly holds the blade away from Castiel. Paired with this is the short pause before Richard turns around - Gabriel is thinking here. He’s trying to think of a way out for both of them. Instead, he falls once again back into the self-sacrificing mentality, but much quicker than he did in “Hammer of the Gods”. To me, this not only communicates his acceptance of his role and his destiny now, but also indicates a complex, but deep bond between him and Castiel. God I’d love this brother bond to be explored more.
Let’s move on to the shove. It’s sudden, it’s desperate, and… it’s weak. Richard’s quite ambiguous with this choice, as it could imply either a hesitation to possibly hurt Castiel, so Gabriel holds back, or show us just how drained Gabriel is. The archangel who once could create a timeloop can’t even move a lesser angel anymore.
The facial expressions are incredible. This is a Gabriel we only started to see in “Hammer of the Gods”. The desperation, the understanding, it’s all so raw and fresh here. This is Gabriel with no filters. There are no masks covering him here, which again, shows us a deep emotional connection between Castiel and Gabriel. Gabriel isn’t afraid of allowing Castiel in, and more importantly, Gabriel uses this to try and persuade Castiel further. You can practically hear “Cas, go!” through lip-reading, and oh god if it doesn’t hurt me.
Another thing I noticed here is this pretty much parallels Dean and Sam’s relationship. Dean being the one who constantly tries to protect his brother, and has been the most self-sacrificing over the series. Makes me wonder if the relationship between Dean and Sam would be similar to the one between Gabriel and Castiel if Sam hadn’t left Harvard to join Dean, and they’d been apart for longer.