Undertale meets Shield

Learning the truth

"Jeez!" Banner yelled as Core just started at Clint who was holding his nose. Thor laughed a little. "M-maybe don't hit them?" Frisk suggested, Core looked at them with an emotionless face. Frisk looked frightened and hid behind Steve, which confused him if this was another version of Frisk. "Now that we got that out of the way..." Stark said, Core stared at him. "Do you think you could help us find this monster?" He asked, Core looked at Nat and got off the chair.

"I can lead you to this Au's W.D Gaster." They said, Nat smiled. "But I must warn you, where we are going is home to many monsters who have been exposed to DT." They said. "But, I thought Alphys brought them up to the surface." Frisk said, Core sighed. "I mean the monsters who fell into the core before Gaster." They said, Frisk's eyes opened for once and they backed away with fear. "You alright?" Banner asked, Core blinked a little as Frisk form changed what looked like their normal selves but with a few scratch marks on their face. Frisk then soon enough bumped into a wall, but that affected them enough to distract them from the task ahead.

"No, no, no." They said and slid to the ground while holding their arms. "Come on kid." Clint said and reached to pick up Frisk, only for Core to grab his arm before he could. "What the he-!" He yelled, Core shushed him. They looked at the now shaking Frisk. Core let go of Clint's hand and held up their own. A screen popped up above them. "Frisk from Horrortale." Core said, Frisk looked up in fear, Core smiled at them. Core then clapped their hands together and that version of Frisk started glitching until it returned to the normal Frisk AU. "Grab them, we don't have a moment to lose." Core said, They were confused as they looked at one another until Thor grabbed Frisk and walked out.

"Where are the hotlands?" Stark asked, Core didn't answer as they waited for the team to come out. "I asked you a question!" Stark yelled, Core looked at him. "I don't answer to those who turn against those who have done so much for humanity." Core said, Clint groaned. "You claim to be this almighty protector when in reality you're just a snotty kid!" Clint yelled, Thor used his hammer to push Clint away from Core. "You want to see what i'm protecting?!" They yelled and balled their fists. "YOU WANT TO SEE WHAT I DO TO HELP THOSE WHO CAN'T HELP THEMSELVES?!" They yelled, Frisk then gripped onto Thor's arm as Core punched the ground, they began to fall until they landed on the ground.

"Ugh, where are we?" Steve groaned as he stood up. "THIS IS MY JOB!" Core yelled, they looked up and were horrified, all buildings were destroyed, no life was seen anywhere and the sky was dark. "I TRY TO STOP THE BAD SANS FROM DOING THIS TO OTHER AU!" They yelled and tears went down their face. "SO THEY DON"T LOOK LIKE THIS AU!" They yelled, Stark got up and looked around. "You said the Bad Sans did this?" Stark asked, Core looked away but nodded. "I knew it, we can't trust him." He said, Frisk got off Thor's arm and walked over to Stark. "Stop it!" Frisk yelled, Stark raised a brow. "He doesn't deserve what you were saying about him!" They yelled, Core looked around again. "CORE me is talking about the ones from Dust tale, the one from Dreamtale, Error, Killer, and Horror!" They yelled, but then sighed.

"In a way, it is Frisk's fault that he turned out like that in different ways." Core said and snapped their fingers and Nightmare appeared. "I remember that joker!" Clint yelled, Core sighed. "This is Nightmare, god of nightmares. Brother of Dream." They said and snapped their fingers again and a happy Dream with his bow in hand appeared. "Dream doesn't seem so bad." Steve said, but then he became black goo and started laughing like a maniac while Nightmare turned back into his normal form while holding his arm and crying slightly. "What the?!"

"If Dream got rid of the last golden apple or ate a negativity apple like Nightmare did then he becomes shattered Dream." Core explained, the rest of the nightmare gang appeared, Dust had his arms folded with his hood up and the red scarf on. "Dust turned everyone, even his own brother to dust in fear that Frisk would kill them all."

"If I took another genocide route." Frisk corrected. "What about Killer and Horror?" Nat asked, Frisk pointed at Killer. "I think you can recognize those eyes." Frisk said, they all turned to him and a picture of their fight with Chara came to mind. "Chara took over Sans body?!" Banner asked, both Frisk nodded sadly. "Horror is just from another AU." Core explained and waved their hand again. "While Ink and Dream protect the AU's." They said and the world around them became white. "I give those monsters who don't have a home a home!" They said with a smile, they looked over to see million different versions of monsters running around in glee. They were surprised with all that was happening.

"OVER HERE!" A monster yelled, one with wings held a ball in their hands and threw it to a girl cat. "What's with the one who has wings?" Banner asked, Core sighed. "Their wings are broken. They came from an AU that was incomplete. Kinda like Inks." Core said. "Ink?" Thor asked, Core sighed. "Ink came from an unfinished AU. He was the only one who had hope until he started going crazy and..." Core stopped and took a deep breath, calming their mind. "You're basically like an orphanage." Steve said as he looked at the monsters. "You take those who have no home and bring them here." Stark scoffed as he folded his arms.

"Boo hoo, so you bring lost monsters to here. Who cares?" Stark yelled, Core sighed. "Is there anything I can do to convince you that Sans and the other monsters in your AU are innocent?" CORE!Frisk asked, Stark hummed as he held his chin in thought. "I want to know what a reset is and what a Genocide route is." Stark said, suddenly, all the monsters stopped what they were doing and stared at him. "What?" He asked as Core covered their mouths. A goth looking Undyne walked over to Stark. "We don't use that word since it was the reason we were all here." The goth like Undyne said as she folded her arms across her chest.

"Wait, wait, wait." Banner said as he waved his hands in front of him. "Your saying that that certain route is the reason your homes are gone?" He asked, dread hung over the monsters. "My AU got destroyed by Error." A human version of Mettaton said with sadness. Stark looked at them all in slight confusion. "You may not realize it," Core said and the avengers looked at them. " but monsters are just like humans, they only want peace to live their days out free. I took advantage of the resets and looked where that got me." Core said sadly and looked at their hands.

"I ended up destroying my AU until it was nothing." They said Clint narrowed his eyes a bit before looking over to see a Toriel that was dressed like Sans while hugging a smaller goat child and another Frisk. Asgore smiled kindly at them. "We believe you." Clint said, Stark looked at him as if he was crazy. "We do?!" Stark and Nat yelled, both showing different emotions. "Good to know." Someone said behind Clint, he yelped when he saw it was Gaster but in a white lab coat and no markings on his face like last time. "Core, when do you think we can eat again? My sons are starting to get hungry." Gaster said as he diverted his attention to Core.

"No need to worry, Sans, Papyrus and Juliet will eat soon enough." Core said, Gaster smiled until someone bumped into his back legs. He turned to see a smaller version of Sans wearing a sweater and black shorts. "Papa!" Sans said as he held up his hands to Gaster who smiled in return. "Who is that?" Banner asked as Gaster picked up the miniature Sans and set him on Gaster's shoulders. "It's one of my Sons. His name is Sans." Gaster answered simply, then an orange dash flew past them.

"PAPYRUS!" A woman's voice yelled as the goth Undyne jumped into the air and caught the orange dash to reveal a smiling Papyrus. "Again, again, again!" Papyrus yelled with glee. Then a skeleton woman passed by them, she had an orange knitted sweater while wearing ripped jeans. They also noticed she had hair but it was made of light orange magic that was styled into a braid. "Thank you Undyne." The skeleton woman said as Undyne handed Papyrus to her.

"No sweat." The goth said, Papyrus was just giggling as the woman playfully scowled him. "And who might you be?" Thor asked once the woman was next to Gaster. "I'm this little troublemaker's mother. Juliet." The woman said, each of the avengers looked surprised while Nat's mouth was wide open. "We should get you guys back." Core said and opened a portal. After about a few minutes of confusion, all but Nat left. Juliet bit her lip and reached a hand onto Nat's shoulder. "I've seen Sans in your AU." Juliet said, Nat looked at the ground with guilt. "I don't blame you but, you need to hurry. Your friend Fury hasn't kept his word and has started testing on my sons." She said, Nat groaned but smiled at Juliet. "Nick never listens to anyone but himself. I'll try to get there as fast as I can." Nat said, Juliet smiled and waved as Nat went through the portal.