A/N: So, this is quite head-canony. Inspired by some other fics/pics I have seen or read, and since I am not intimately familiar with Tolkien's afterlife, perhaps not as faithful as it could be. It is also probably quite an angsty attempt at a fix-it fic. But I hope you enjoy!
He came fighting into the silent halls, a wild creature clawing helplessly at the hands of death, and it seemed, at first, that he would never rest.
Blood stained his mail, his hands, his face, but he would not allow his wounds to be healed by the touch of the eternal—he staved off every attempt, clinging fiercely to what had once been life.
There was a stirring in the shadows, a shaking of the lofty pillars.
"Son of Durin," came the great voice, ringing like a hammer on ancient stone, "Be at peace. Your days have been counted and made good."
Fili pressed his shaking hands tighter around the hilts of his blades, lifted his eyes to gaze upon features that were not mortal, scarce definable, and yet more familiar than he had expected.
"Maker," he whispered, and he felt his wounds fade along with his spirit. He knelt low and bowed his head, but the words would not go unsaid. "Let me go back! My brother is young—and he—he is reckless, he will fight for me, I must save him…please."
And the face of the Maker, ageless and kind, looked long upon him, and Fili felt his heart break even as it was filled with gladness.
"Fili," said Mahal, with a voice softened to the patter of rain, "Your brother is already here."