AU: Hello everyone! First time fanfic writer here. I will keep the more detailed version of the story description short and sweet.

The story is about Hiro Hamada in an AU. He doesn't take finding out Callaghan killed his brother so easy so things take a turn for the worst. Alternate ending

The Kabuki mask found its way off of the viallain's face as Him in Hiro tumbled down a small flight of steps and slid to a halt, face down. Hiro was the first to get up, he saw the Kabuki mask with the neurotransmitter attached to the back of it. He picked it up with cat-like reflexes and stood up. He looked to the man who was slowly getting up to his feet.

"It's over Krei"

The man stood up and turned to face hiro. The man was none other than Professor Robert Callaghan. The whole team gasped in shock of seeing the professor alive.

"P-Professor Callaghan?" Hiro said as he looked in shock at Callaghan

"Y-You died"

Callaghan walked up to Hiro in an intimidating manner

"No, I had your microbots"

Flashback

Professor Callaghan puts the neurotransmitter on and the microbots surround him in a spherical shield, as the fire engulfs around them.

End of flashback

Hiro looked down to the floor in thought and looked back up at Callaghan

"B-but Tadashi, you just let him die"

Callaghan steeped forward reaching out his hand

"Give me the mask Hiro."

Hiro stepped back with tears in his eyes and anger building up inside.

"He went in there to save you!"

"That was his mistake!"

Hiro's eyes widened in shock and then narrowed in anger. Moments later Baymax landed behind him. The team looked at Hiro with concern and confusion as to what he would do next. His next statement gave them their answer.

"Yes. It was" Hiro looked at the Kabuki mask and then at Callaghan.

"A mistake I won't make. Baymax destroy him."

Gogo, Wasabi, Fred, and honey Lemon looked at Hiro in shock and horror. Baymax bent down to look at hiro, and in his calm robotic voice said

"My programming does not allow me to harm a human being."

In an angered voice Hiro said "Not anymore."

Hiro took out the healthcare chip from baymax and looked at it in question.

"Hiro this is not what Tadashi would have wanted?"

Hiro took one more look at the chip and let out a tear before saying "Tadashi's dead!" Hiro then broke the chip in half and threw it on the floor. The team now knew something horrible was going to happen and readied their weapons.

Hiro pushed the red chip back into baymax and the robots eyes began to glow a bright red.

"Do it Baymax, DESTOY HIM!"

Baymax's rocket fist launched and hit the wall, missing Callaghan. The fist then flew and reattached to Baymax. The team then rushed in to action to try and stop the robot. Gogo was the first to come in contact with Baymax, she slid down the railing and jumped on His right arm causing the robots second shot to Miss Callaghan twice.

"NO, stop it Baymax!"

Baymax pushed Gogo into a wall and his rocket fist reattached. Callaghan was running through a series of support beams and tripped. Baymax looked at Callaghan with his glowing red eyes and approached Callaghan, knocking down the beams as he did so. Baymax prepared for another shot and then Fred jumped behind on Baymax's back, throwing the robot off balance. Baymax began leaning back and slammed Fred into a wall. The rest of the team then approached and started to slow down the robot.

Hiro looked at the robot slowing down and Callaghan getting close to the exit. Hiro looked down at the mask and took out the neuro-transmitter from behind it, He lifted up his helmet's visor and put the transmitter on his head. Then he closed the visor to avoid the transmitter falling off.

The microbots then started spinning and surrounding underneath Hiro's feet, lifting him up 30 feet. The team looked at Hiro with fear and got distracted from baymax, long enough for him to throw them off. The team slammed hard into walls causing them to get knocked out. Hiro looked at the unconscious college students and then to Callaghan who was only feet from the exit.

In a quick motion Hiro used the microbots to slam in front of Callaghan, knocking him down and destroying the exit. Callaghan leaned up and saw Hiro approaching him with the microbots wrapped around his waist. Callaghan quickly got up and started running the other direction, only to be caught and encased by the microbots.

Hiro used the microbots to bring Callaghan to eye level. In a menacing voice Hiro said

"Where do you think you're going?"

"P-Please….I, can explain."

The microbots squeezed Callaghan causing him to yell in pain.

"I don't care what your explanation is! It gave you no reason to leave Tadashi inside that building! He looked up to you, you were his idol, his mentor! You were the closest thing he said he had to a father, and you let him die!"

Callaghan tried to muffle a word out and struggled to say, "A…..Abigail….."

Hiro loosened his grip on Callaghan and raised an eyebrow

"Who?"

"S-She was...my daughter. She was taken from me by one of Krei's experiments, she was all I had left after my wife died. You see, I had to steal your microbots to avenge her"

Hiro felt a little pity for the man and frowned. But it quickly turned back into anger and he started to crush Callaghan again.

"Revenge solves nothing!"

"W-Well what do you think you're doing?"

Hiro leaned back in thought

"Huh, good point."

Another wave of anger started from Hiro and he menacingly looked at Callaghan again.

"But stealing someone's invention, killing their brother….Abigail would be ashamed to call you her father."

Callaghan was shocked by that remark and frowned. He was going to respond, but then realized Hiro was right, Abigail would be ashamed of him. Callaghan leaned his head down. Hiro then remembered what him and the rest of the team saw. Hiro looked at the last piece of the portal that remained on the stand.

An idea popped into Hiro's head, a rather horrible one.

"So you say you want to see your daughter again? I think I can help with that."

Callaghan looked up a little confused.

"What do you mean?"

"I mean, you will see her again, but not how you think."

Hiro smirked and Callaghan realized what he meant. Hiro started to move him and Callaghan to the portal and grabbed it using the microbots.

"N-No, What are you doing?!"

Hiro looked at Callaghan with the smirk still Present and said

"Avenging my brother."

AN: Well, there's chapter 1. Hope you like it, please review. I ask you keep it clean if you hate it. Just a heads up, I have the next few chapters written in advance and believe me it will get better.

Help me reach my goal of 20 positive comments. BYE.