Pinkie was about to kill Macy when May appeared.
"STOP!" she yelled, throwing a hoof around Pinkie and holding her. "DON'T DO IT!"
Pinkie slowly closed her mouth and let Macy go.
"May..." said Pinkie.
"STOP ALL THIS!" May cried.
Twilight was shocked by the scene. She suddenly saw a part of the old Pinkie in Pinkamena's eyes. They looked sad.
"May... I..." she whipped around and tackled May to the ground. "have to."
She opened her mouth and dug her teeth in May's chest. May let out a yell of pain. Macy leaped at Pinkie, knocking her to the ground.
"PINKIE!" she yelled. "STOP THIS! WHY ARE YOU EVEN DOING THIS?!"
"BECAUSE!" yelled Pinkie, crying. "I HAVE NO FRIENDS! AND THE ONLY FRIENDS I HAD BETRAYED ME! DO YOU KNOW WHAT'S IT LIKE TO GROW UP WITH NO FRIENDS?! IT'S HORRIBLE! I HATED IT!"
"YOU DO HAVE FRIENDS NOW! LOOK AROUND!" Pinkie looked at all of her old friends as well as her new friends. "THEY ALL CARE ABOUT YOU! EVEN AFTER YOU BECAME THIS MONSTER! AND THE ONLY ONE WILLING TO FORGIVE YOU IS NOW LYING RIGHT THERE, BLEEDING TO DEATH BECAUSE OF YOU!"
Pinkie looked at May and a tear fell from her eye.
"May..." she said softly.
Pinkie covered her eyes and started to cry.
"It's working." Twilight said softly.
"It sure is." responded Applejack.
"I DON'T KNOW WHAT TO DO ANYMORE!" cried Pinkie. She took a deep breath and started to calm down. "There's only one thing left to do."
"What's that?" asked Macy.
"Kill me."
This request caught everyone off guard.
"What?" asked Macy, shocked by what Pinkie said.
"Kill me." Pinkie started crying again. "Kill me before I get the chance to turn again."
Macy hesitated but eventually levitated a piece from one of the smashed carts and brought it over. She held it above Pinkie's chest.
"Hurry." said Pinkie. "Do it."
"Pinkie..."
"You have to." pleaded Pinkie. "I don't wanna kill anymore."
"No, Pinkie. I--"
Pinkie's eyes narrowed and she opened her mouth. She sat up to try and bite Macy's face. Macy took a deep breath and plunged the wooden splinter into Pinkie's stomach. The angry expression on Pinkie's face became sad again.
"Thank you." she said, falling back down.
Her breathing turned raspy as she lay on the ground with a wooden splinter in her chest. Macy got off of her and the others gathered around Pinkie and May. Everyone had tears in their eyes.
"Rainbow Dash?" asked Pinkie, weakly.
"Yeah?" Rainbow Dash said, kneeling down next to Pinkie. "I'm here."
"I'm sorry. For everything." She paused as she coughed up a little blood. "I shouldn't have hurt you. Your my friend." She looked around at all of her friends. "You're all my friends. And Fern..."
Fern knelt down next to Rainbow Dash.
"Yeah?" she asked, crying.
"I'm sorry I made you do all those things. And I'm especially sorry that you had to help me kill May's friend." She coughed up a little more blood. "That was my greatest regret."
Pinkie felt as though she was going to die at any moment. So she grabbed the wooden splinter and yanked it out of her. She placed a hoof over the wound and scooted closer to May. She then held out her free hoof and placed it on May's hoof. She then looked into May's eyes, and May looked back into hers.
"May..." Pinkie started. "Back in the cave..." She coughed up more blood. "Killing wasn't the only thing I cared about."
May started to cry harder when she realized what she meant.
"Oh, Pinkie."
"Please." said Pinkie, choking on her last bit of air. "Forgive m..."
Pinkie's last breath escaped her lips and her whole body became limp. A final tear escaped her eye as they closed. Forever. The night had fallen quiet. The only sound that could be heard were the cries of those who just lost a friend.

Celestia stood out on a balcony of Canterlot Castle, observing what was going on in Ponyville. A tear fell from her eye, too. She smiled and turned, heading back into the castle.