Author's note: I know that the last chapter is really short and bad, so I wrote a longer one, and I also turned Nightmare's bow tie and top hat purple, that was intentional, you will see why later in the story. Enjoy!
Luigi and Mario arrived at Bowser's castle, "Bro, aren't you sick of Bowser keep on kidnapping Peach?" Luigi asked, "No, in fact, I enjoyed" Mario replied, "Even though I already memorized all of his trap's pattern and, well, the entire castle's layout. I guess he never bothered to change his traps."
The brothers walked up to the castle's front door. The front of the castle is designed to resemble Bowser's head, and with his mouth as the door. And like always, the door to Bowser's castle opens. "Welp, here we go again." Said Mario, as the brothers plunge through the doors.
Nightmare has been digging his way out for hours, apparently, he has been buried pretty deep. After an hour, he broke through a layer of dirt when his claws meet the air, at first, he thought it's nighttime but in a closer inspection. Through his night-vision eyes, he saw a jagged surface on top of him, and that is when he realized where he is, he is in a cave. Nightmare crawled out of his hole, and look around. It appears to be a large cave, a really large one, too large to be a natural cave. And that's when Nightmare notices a table, it's a metal table, with rust forming on its sides, it looks abandoned, in fact, this whole man-made cave looks abandoned.
'Huh, interesting,' thought Nightmare 'I have apparently discovered an abandoned underground workshop.'
He can tell, through the rusted tools. And the wires sticking out of various rusted machines that he just noticed, and the undisturbed thick dust. He picked up a drill and switch it on, and to his surprise, the drill actually works. It made squeaking sounds as it spins, but nevertheless. It's still working, Nightmare switch the drill off and look at the other tools. Perhaps he can find some use of the tools.
The brothers approach the throne room, and just as they expected, there's Bowser, and Peach dangling from a cage.
'This is going to be fun.' thought Mario,
'Oh boy, here we go again.' thought Luigi.
Bowser hopped down from his throne and land with a heavy thud, "So Mario, you came again. You have the bravery to fight me! The most powerful, invincible-." "Yeah, yeah," interrupted Mario, "I get it, and let's just get to the fighting part." Luigi slapped his face and chuckled behind it.
"Oh? I see you brought your brother with you, who is it again? Well, it doesn't matter," said Bowser. "I shall kill you and your brother, Green Mario, and take over the Mushroom Kingdom!"
"Good luck on doing that," Mario said, smugly. "Oh, and my brother is called Luigi."
Mario walked towards Bowser, "Oh? You're approaching me?" taunted Bowser
"I can't beat the shells out of you without getting closer," replied Mario.
"Then come as close as you like," said Bowser.
And the fight begins.
Nightmare. With his knowledge of engineering,(he is an animatronic himself, he gotta learn how to repair himself) has created a driller that is designed to drill through rocks. 'I will escape,' he thought, 'I will escape the underground, and find that mortal so I can consume his fear and become unstoppable, his fear has awakened me. So I shall take all!' And with that thought, he switches on the drill, and begin to drill through the wall.
After an hour or so, a stream of daylight shone through a crack that just formed and hit Nightmare square in the eye. He roared in pain and dropped his drill, which broked apart due to the rusty material that it's made out of. But it has done its job.
Nightmare stumbles back and quickly covers his eyes, not wanting more light. But he recovers and uncovers his eyes, what he saw, filled him with an insane amount of joy, and happiness. "Finally, I will be free," He laughed, "I shall escape this prison and become invincible." but, he still can't escape, not yet because it's daytime. But that does not bother Nightmare, he can finally be free. And escape his prison once and for all.