Arthur had seen dead men before. In truth, he'd caused many deaths before, the act of killing no longer even especially noteworthy. When a knight fell, it was tragic, of course, but Arthur knew that they had given their life for Camelot.
This was different. He knelt on the ground next to the unmoving figure, still warm, still looking exactly like Merlin. It was Merlin, and it wasn't. The stillness, the blank, unfocused look in his eyes, and the slack way his mouth hung half-open, that was not Merlin. The messy hair, the neckerchief, the familiar way his hands lay, even at rest, those were all Merlin.
In this moment, everything was the body on the ground next to him. Arthur could see nothing, hear nothing but the fact that Merlin was dead, and would be dead from now on, forever. All the details he didn't want to see were flowing over and through him as he stared. Blood still pooled from his head, crept across the ground and into the handkerchief at his neck. Merlin's limbs had bent at odd angles as he had fallen, and Arthur wanted to straighten them out, to make his friend more comfortable, but he couldn't bring himself to touch him. Not that it mattered, he knew, but the contradiction wouldn't leave his mind. This was both Merlin, and not Merlin, and if it was Merlin, Arthur would take care of him.
Arthur's breath hitched suddenly, a small grunt escaping from his throat before he bit it down. Not yet, he couldn't afford to feel this loss just yet. He looked up to check on his men, to see if the battle was still raging. It wasn't, and the stillness, the ringing silence that came with the end of something big. It was broken with the cries of the wounded, the sound of horses and of his men shouting for each other and for him.
Things were choppy, surreal. The air had a glow to it, and Arthur couldn't quite seem to get his head right. Everything was different. He didn't know what to do. He watched as Gwaine noticed him, still on his knees next to the body. It was as though time had come nearly to a stop; Gwaine's face fell, practically collapsed in on itself as he took in the sight of Arthur on the ground, and Merlin, unmoving, laying next to him.
"Merlin! Merlin, no!" Gwaine sank to the ground next to them, grabbing Merlin by the shoulders and shaking him roughly. The sight nearly made Arthur sick, and he had to turn away and squeeze his eyes shut as Merlin's head lolled back, and he flopped bonelessly as his body was shaken.
The movement had jostled Merlin to the side, revealing the wound and the puddle of blood beneath him, and Gwaine pulled away, hand to his mouth. He fell back, then turned to the side and was sick on the ground. Arthur still hadn't moved. He could see Leon, now, and Percival. They had clearly seen Merlin as well, and were standing back, looking horrified. Leon had his hand on Percival's arm, appearing to hold himself back as much as he was holding his friend.
For some time, they stayed where they were, all movements small, stilted, as though any movement would be too overwhelming for them. Arthur shook, slight tremors that came and went, threatened to make him lose his balance, and eventually, he felt Leon's hand on his shoulder, steadying him. Arthur hadn't even seen him move.
With a deep breath in, Arthur stood, squaring his shoulders. Now he resolutely looked ahead, instead of down at the body. At Merlin, or what used to be, or what was and wasn't Merlin. Later, he would sob over the loss of his friend. He would miss Merlin for years, the loss would catch him in moments he never expected, and he'd feel the emptiness in his chest. He'd go home to Gwen, and she would know without him telling her. They would cry, too. But for this moment, he was the king, and he needed to take his men home, alive or not.