Castiel knows what Naomi wants. He knows that Dean is pleading for his help, that Sam is begging for strength.
That Samandriel's blood is on his hands and the blood of countless angels.
He hears Dean's prayer in his head, over and over again, hears the desperation in his voice.
Hears Sam's pain, sees him cough red onto his hands. Fingers gripping the sink as crimson comes out in spurts, mouth open and teeth stained scarlet and all that he asks is that he be granted strength to follow through and carry on.
And that, when he is gone, as is inevitable, his brother be given that strength too.
And Castiel knows everything and Naomi calls him but he digs the angel blade into his palm as the throbbing grounds him, keeps him tethered to earth.
It isn't hard to find them, their fetid breath released in long baying howls, all too hungry to tear his Grace to shreds. He kills the first two, tosses their bodies aside.
But the last one, the third, he falls with it and cuts it open from neck to belly and down as black, black blood bathes him, covers him and burns and all he can think is that he is glad he removed his trench coat, standing then as pain grips his left arm.
And his grin is ferocious, because the tablet never said that an angel, fallen or nearly there or maybe more than that (friend and guardian), could not make the deal to close the gates of hell.
Apotheosis: The hero will be submitted to death in some way or form. It begins with the hero's recognition of the divine within himself.