Here we go.
Andrew came into the office with Twilight in tow. "What is it Discord?" he hissed. It was a well known fact Andrew only ever showed any respect to Twilight, though no one knows exactly why.
"Simple, I was hoping the King of the Night could show a new student around school." the headmaster replied. "Cadence, could you send in the new student?" he called over the intercom.
A few seconds later, the door opened to reveal a gray skinned, pitch-black haired boy in the school uniform. "Hello, I'm Sombra Darkcrystal."
"This way. We'll start with the cafeteria and work our way to the front." Andrew hissed before leaving.
...
"So, this is the school I've wanted to enroll in for three years. Ug!" Andrew slammed Sombra into the wall, Twilight standing in shock.
"What are you doing here Sombra?" Andrew demanded, "I know you, you wouldn't leave Equestria even if you fell victim to the Elements." Sombra laughed.
"I'm sorry, you have me confused with somepony, whoops." Sombra giggled.
"Don't play dumb. You're nothing compared to the darkness, and you're nothing compared to me. If you have any plans that endanger anyone in this world, I will stop you." Andrew released the boy with more malice in his eyes than anyone had seen before, and lived to tell about it.
"I'm curious, does K.O.N live?" Andrew didn't answer as he lead Sombra through the school, Twilight pointing out classes.
...
"I should have known I wouldn't have been able to keep my past from catching up to me." Andrew hissed. They were back in Twilight's lab, Twi tapping away on her computer. "Anything?" he asked.
"Not before three years ago, it's like he just appeared." she responded. "Just who is this guy? It's obvious you know."
"He's a tyrant who enslaved everypony in the Crystal Empire. It was only because of Princess Celestia and Luna that he was brought down. Some say he wasn't always like that. No matter what the case, we need to keep an eye on him. Sombra isn't one to give up easily."
"What if he's just looking for a fresh start like you were?" Twilight asked. "Don't forget, in the Shadow Garden you weren't exactly Mister Benevolent." Twilight swerved in her chair. "Give him a chance. You already warned him what would happen if he relapses."
"Have to try to go straight to relapse, but you're right. We should give him the benefit of the doubt." Andrew sighed. "Come on, we're going to be late to P.E." the duo stood and left.
...
After school, the duo stood in front of the school. Twilight turned to her friend. "We still on for Mortal Kombat tomorrow night?" after a grin and a nod, Twilight boarded the bus and it drove off.
Andrew began walking. Down the street and towards his black stone house. "Don't shoot, it's me." he called before opening the door to see his roommate, Time Turner, holding a slingshot. "How was school?" he asked, sitting down on the tan couch.
"It went rather well. Derpy sends her regards." Andrew smiled as he reached for the controller. "Law and Order, if you don't mind." Time said.
"Regular or SVU?"
"SUV if you please."
"Remember, I have company tomorrow." Andrew said mildly. Time nodded and they enjoyed their show.
...
Andrew stood at the front of the school, waiting for the bus that always brought Twilight. As he sat down, he saw Sombra heading towards the headmaster's office. "What is he up to?" Andrew muttered.
"Probably going to apply for the Games." Andrew whipped around to see Twilight standing over him. "I thought we were going to give him the benefit of the doubt." she said.
"Doesn't mean I can't keep him in sight. You ready for the Games next week?" Twilight nodded. "Good, we need to be ready if they have Equestrian magic to boost them."
"Will this be the year you finally use your powers?" Andrew was already shaking his head.
"I won't cheat, but I will use my skills to make sure there's no cheating from the Wondercolts. Hey, did Discord tell you there's going to be a tag-duel event and I think we could win."
"Andrew, you know I can't duel." Twilight huffed.
"You can duel circles around me, you just don't want to think you're good at something other than school." Andrew snapped. There was a small bark from Twilight's pack, "Yeah, I know it's mean Spike, but... wait a minute, Spike?" the purple and green dog poked his head out of the open zipper. "Twi."
"He wanted to come with me tonight, I couldn't say no to that face." Andrew rolled his eyes and laughed. "What, is it so funny that I can be manipulated by my dog?"
"Yes." Andrew laughed as he stood. "As far as the duel?"
"Lightning is the only other choice, so I guess some monsters with some brawn would be in order. Sparring match during lunch?" Twilight asked, bringing out her deck.
"Your on." Andrew said, "But we should finish the duel disks first." the friends ran into the lab.
Yes, there is a slight Yu-Gi-Oh crossover, but only a couple duels are going to be in it. Don't forget, I love reviews and comments!