Stories I can't make

Pinkie was about to start on Rainbow's Cutie-Mark when....

"Ugh...," Pinkie uttered as she clenched her chest and a dark demon came out, falling onto the floor.

"W-What happened?" She asked herself. She noticed Rainbow, tied up and quickly recalled what happened and only gasped, after which, quickly untied her friend. When she lept from the harness, she knew Pinkie was back if she untied her.

"I knew it was the Lunacy." Luna suddenly appeared. "It was controlling you, desiring gore and blood." Pinkie blew a raspberry at the dark being, but noticed a weapon randomly on the floor for a last resort. Pinkie picked up the gun and pointed it at the Lunacy.

"Th-Th-Th-That's All Folks," She said, shooting the gun at it's head. After it collapsed, it rotted away, confirming that it died.