Most Powerful Monster

Chapter 9

(Y/N)'s POV

We just ate some spaghetti that Papyrus made, it was really good. It looked like my tips improved his cooking greatly according to Sans. I could live with eating Papyrus's spaghetti all the time.

Papyrus said he had to go training with someone named Undyne, and he invited Sans and I to come along. Papyrus mentioned that I should come along to meet Undyne since we were going there anyways. Sans was worried at first, but Papyrus convinced him that nothing bad would happen. Sans made it clear that if anything went wrong, he would sort it out. It was so cute that Sans, who always seemed laid back and relaxed, could be that protective. I'm glad that Sans and Papyrus were my "brothers".

After a good 15 minutes of walking, we arrived in front of a house that looked like an angry fish. It had two windows that acted as eyes with a door in the middle that looked like a mouth. Papyrus shuffled up to the door and knocked. A few seconds later, a fish-like woman opened the door. She had blue skin with fins on the side of her face, a long, red ponytail, one yellow eye, and an eyepatch. She wore a black tank top, blue pants, and red boots. She smiled once she saw Papyrus. "Hey, punk! Ready for your warrior training?" she asked Papyrus. She had a rougher voice, much like a tomboy's. Papyrus was blocking the way, so Undyne couldn't see me or Sans. He glanced behind him to look at the two of us and back to Undyne.

"U-UH YES, UNDYNE, BUT I ACTUALLY BROUGHT SANS—" Papyrus started, but Undyne interrupted Papyrus.

"Cool. Sans hasn't been to one of your trainings before. Maybe you can even train with him, too." Sans just shrugged at that. I guess Sans and Papyrus have trained together before, just not at Undyne's.

Papyrus tried to speak again, "THAT'S A GREAT IDEA, UNDYNE, BUT I BROUGHT SOMEONE ELSE, TOO." At this, Undyne raised her eyebrows, and Papyrus stepped aside to reveal me and Sans. Her eyes widened once she saw me, and she bared her teeth; a spear appeared in her hand. This wasn't good.

"A human!" Undyne shrieked and lunged her spear at me. The attack was too sudden, so I couldn't summon a wall of ice to protect myself. I covered my head and hoped for the best. It never came. I looked up to see Sans standing in front of me, left eye blazing and his hand extended with the spear encased in a blue aura.

"Sorry, Undyne. That's not how this game's gonna go down," Sans growled. Sans flipped the spear around, so it was aimed at Undyne. Undyne looked surprised and even a little scared. I'm guessing that was the effect Sans was going for because he snickered. "You hurt my sister, you're gonna have a bad time." Undyne gasped and backed away. I was just as surprised. I stared at Sans. He called me his sister. Undyne lifted her hands for a second to show she surrendered. With that, Sans's eye stopped glowing, and he put his hands in his pockets. "Good," Sans smiled.

"S-she's yo-your sister?!" Undyne stammered. Sans nodded without hesitation with Papyrus following. She glanced at the skeleton brothers, dumbfounded. "You do realize that we could use her—" Undyne stopped herself from continuing because Sans's eye started to glow again. "N-never mind," she said glumly, looking at the ground. Sans's eye flickered out again. I glanced at Undyne and Sans nervously. Tension was very high and dangerous. 

Before I could think of something to say, Papyrus butted in, "Should we start our battle training now?" Undyne looked up at him then to Sans. He nodded approval, so she nodded approval to Papyrus. Undyne led us to the back of her house where a big yard laid out in front of us. Sans and I sat on a bench that lay against the house, facing the yard. Sans was sitting there as if nothing had happened.

"Thanks for defending me back there," I told Sans. He smiled down at me and ruffled my hair.

"Anything for you, kiddo," Sans said.

"and for seeing me as your sister," I added. Sans looked a little surprised at that but shook it off and hugged me.

Meanwhile, Papyrus and Undyne got into position. Papyrus's right eye started to glow orange, and Undyne summoned glowing, blue spears. My eyes widened in surprise, and I looked up at Sans. He saw my expression and started to laugh. "Don't worry, kiddo. They do this all the time. They don't kill each other. They're just practicing. They'll stop if it gets too far," Sans assured me. I let out a sigh of relief and continued to watch them train.

After a long, long time, Undyne was victorious. While they were fighting, Undyne gave some tips to Papyrus. They both fought really well; Undyne said that was the toughest fight she had with Papyrus. Both of them were sweating.

"I have an idea!" Undyne said breathlessly. We all turned to her to listen to her idea. "How about we have a tournament? We all fight each other to see who's the strongest." We all nodded in agreement. "Besides, the human can learn to defend herself, too, right?" Undyne aimed the last question towards Sans. Sans looked really concerned but finally gave in and nodded. Undyne nodded and continued, "So, next up is Sans vs. Papyrus." The two skeletons looked at each other and smiled. They walked over to their positions with Sans looking back at me and Undyne sitting together on the bench. I gave a thumbs-up, and he reluctantly walked over to his spot. While the fight was going on, Undyne and I got to know each other more. We shared laughs and secrets, even. Not too long after, Sans won the fight. He smiled as he saw we were friends now; Papyrus was happy to see that, too. Both of the skeletons were sweating, but Papyrus was sweating more.

"Should (Y/N) and I fight next? I could give her some tips, too," Undyne asked. The skeletons nodded and took our spots on the bench as me and Undyne took our positions. I was nervous about this. Undyne looked very powerful when she fought Papyrus. Plus, I would have to show her my magic. The fight started and it was my first move. I summoned icicles and shot them at her. Undyne dodged all of them, but stared at me in shock once I was done attacking. "You have magic?" Undyne asked incredulously. I nodded my head shyly. The surprise melted into challenge. "Well, then. This outta be interesting," she smiled. I was happy she wasn't scared or shocked out of her mind. "Let's see how well you dodge, punk," Undyne challenged. She summoned some spears, and I dodged all of them with ease. She cocked an eyebrow and awaited my response. I raised both of my glowing white hands and shot snowballs at her. This went on what seemed like forever until I finally pinned her in a position she couldn't get out of. "Alright, alright. You win," Undyne concluded. I waved away my attacks and helped her up. We walked back over to the bench where Sans and Papyrus were waiting. "She's strong. I didn't even need to give her tips," Undyne reported to the skeleton brothers. They all congratulated me, and we moved on to the next match: Sans vs. me. I was tired from the last match, but I didn't let that stop me.

We both got into positions, starting with his first move. I was scared. How strong were his attacks? After all, Flowey did call Sans the most powerful monster in the Underground. "It's a beautiful day outside. Birds are singing, flowers are blooming. On days like these, kids like you-well, I'm not gonna finish that because what I say next doesn't apply to you," Sans said. I was confused, but I couldn't think about that. Sans's eye flashed on, and he started his attack: first with bones bursting through the ground underneath me, a wave of bones, and gigantic skulls shooting at me. I got hit a few times, and the wounds stung. That was just one attack?! "Huh. I always wondered why people never use their strongest attack first. Wait, are you OK?" Sans commented. I nodded and readied my attack. He wants to use his strongest attack? OK, two can play at that game. I summoned icicles to shoot out underneath him with more icicles surrounding him on top. Sans smirked at me. I swatted my hand down making the icicles on top launch at him. He jumped up, avoiding the icicles shooting up from under him and slid to the left to avoid the icicles on the top. Once the attack was done, Sans stood up, brushed his shoulders and gave me a big grin. I let out a sigh and shook my head. The rest of the fight was difficult. It took forever. Both of us were strong, but Sans won. He pinned me by surrounding me with what he called Gaster Blasters on all sides. I was so tired, I couldn't manipulate my magic to protect me, so I surrendered. We were both sweating like crazy. "You . . . did good," Sans panted as we all sat down on the bench. Everyone congratulated Sans, they even congratulated me for lasting so long.

"Our last fight is Sans vs. me, but it would be unfair if I fought him while he's in this state, and I'm well-rested," Undyne pointed out. I was exhausted, so I all I could do in response was yawn. In a blink of an eye, I fell asleep right there on the bench.