Disclaimer: I do not own or take credit of anything below, besides the liberal use of the original author's literary world. Everything else belongs to JK Rowling.
The Last Stand
He was going to die. He knew that.
As the thought formed in his head, he knew it wouldn't take long now. He saw the curse one of the Dark Lord's followers threw at him before the crippling pain in his leg hit him. That shade of burgundy was not in his repertoire, and he could feel the maliciousness only a truly Dark curse emanates. Yes, it was that one that did him in. Not the multiple slashing hexes that made it through his shields. Gideon and he usually made a game of it; counting how many slashes were from curses and how many were from rolling around in the battlefield. Gideon...
A sharp pain registered, more painful than the one in his leg. His other half, his bestfriend. His soulmate. His twin.
He looked past his arm, with his dented golden watch, and saw him.
Eyes wide open, staring into the distance and a slack face. Gideon.
The last thing he saw of his brother alive was the flaming whip curse Gideon struck Dolohov with. In the crown jewels, as it were. The bastard will have a nasty reminder of why you don't piss off a Prewett. Good. He hoped it hurt and made him squeal like a stuck pig.
Turning from Gideon, he looked around, as best as he could. From his position on the patch he was occupying, he could only see the two wizards he duelled and killed. He knows that Gideon felled at least two others, but he couldn't see them from here. The nearest one still had his mask on, the other didn't but he couldn't see his face properly due to the blood and gore on his face. He hoped Dolohov died, Russian bastard ruined so many lives.
He was glad that Molly didn't join the Order with his brother. They had one of the biggest rows they had ever had when Molly, Prewett temper upped to eleven, demanded to join. If it wasn't for Arthur, kind and sensible Arthur Weasley, she might have been right here, next to them. His adorable nephew William would have lost his mother. Arthur his true love...
The curse had spread from his leg, he noted. He must have been so consumed in his pain for the death of his twin he didn't notice until now. He couldn't move his lower half and there was a tightness now to his torso, besides the creeping pain. He turned again, and looked into his dead brother's eyes.
As his last breath was expelled, Fabian Prewett was at peace, near his twin.