Lucifer/Sam + Michael/Dean
Michael had been waiting for this moment for a very, very long time. Anxious, dreading, but waiting, because this was predestined, and until this was finished, Michael would never know peace. Lucifer haunted him - not in the way the insignificant spirits of the dead and damned of this planet haunted. It was a different sort of haunting - it was the looming dread he felt when he considered his blade piercing the heart of his beloved brother's Grace with the blade that lit bright like flames in the presence of darkness. It was in the doubts that he forced himself not to have, even when the humans questioned him, questioned Father and His Will.
Michael refused to have doubts. He did not need them; he had orders, and that was enough. Surely, this was right.
It was time for this crippled and broken world to have its peace.
Michael had been standing in the garden above the burial grounds all night. It was peaceful, there, and there was a certain symbolic comfort in the place; praying in a garden before an event that must be, but was dreaded. If it be Thy Will, he had breathed towards the sky, knowing he would not be heard - or that if he were heard, his prayers were not heeded. It did not matter. He had his orders, why should he need anything else? Comfort and reassurance were for humans. Michael was an Archangel. A warrior.
The gathering beings below - some human, some twisted parodies of human shapes, some foul, blood-drinking monsters who pretended humanity - held his attention for only so long. He could sense Lucifer nearby, knew exactly where his brother stood. His hesitation was not doubt. It was another prayer, a plea for strength that he knew he had, another unheeded whisper towards a Heaven full of angels as confused and conflicted and tired as he was.
His vessel's spirit shifted inside, restless, and Michael crushed him back down, before steeling himself and appearing, in a fluttering rustle of feathered wings, behind Lucifer.
"Call off your army. They will do you no good." If he wished, Michael could have sent for a thousand angels to storm this place, sweep away the abominations and carry the deserving human souls to their eternal reward. But this was not the time or the place for his angels; this was Lucifer and Michael, and no one else.