The best that princess Celestia, Cadance, and Luna could do were to have eight coffins. Twilight and Spike were in their coffins, but there were no remains of the other six that died. So, in Rarity's was the knife that Spike used, and a few dresses that Cadance had. Rainbow's coffin had a lightning necklace in it. Fluttershy's had a few leaves, and some of Angel bunny's food.
Pinkie pie's coffin had a bunch of party supplies in it. The coffin of Applejack had an apple and some coins. This is what's left of them.
The bounty hunters were sent to the arena like Spike. This was because of the one that hit Twilight. Over a year, Shining Armor watched with pleasure as they were selected, and one by one were all killed but the last pony. This pony thought he could be like Spike, but apparently he couldn't. He thought Spike had fighting skills and blindly ran into an escape.
So he made a prison knife, and called the guard over. He wore the uniform after killing the guard. The problem wasn't that he didn't have a plan. He wasn't organized, and he wasn't thinking about a story of how he was there.
He was quickly caught because he had blood on the uniform, no one has seen him, and he didn't have his spear. Then he thought he could fight. Instead, he got three holes stabbed into him, dripping blood. He gave up, and instead of fighting to death in the arena, he was hung.