[Great. So the only person who knew that Castiel was about to walk into a bonafide angelic trap was Rei. Who was also the only person in Adstringendum, that she knew of, that could trap an angel long enough to not die.

It was stupid not to have her go, as an insurance policy. The other angels wouldn't think anything was off -- none of them knew that Rei could control holy fire except perhaps Lucifer and even he didn't know what she could do with it. Having her not go wasn't calculated or strategic, it was dumb.

And even if she couldn't be the one to go, why not Gabriel or Anna or any other angel that could actually assist Castiel? And not telling Dean didn't sit well with her, either.

She closes her eyes for a moment, to count to ten -- because losing her temper on Castiel wasn't going to help. But the more she counts to herself, the more frustrated she becomes, until she finally snaps:]

Nothing about this mess is calculated or strategic, Cas! It's stupid. This entire plan is stupid. There's no way that Raphael will just let you walk away when she has a shot to kill you -- you said that yourself. There are some things worth dying for and this isn't it.

You know how badly it hurt when Anna died. Do you really want to throw your life away when there's a way out and give other people the same pain?