A/N I don't own Kingdom Hearts nor the Avengers but I do own this story. This is part one of the final battle and yes... it will include Cloud vs. Sephiroth and it will be based on Advent Children but that happens in part 2.

Before they get on the quinjet, Cap and Sora readied their weapons to prepare for battle. Tony is loading up a new AI to help him like Jarvis.

"Good evening, boss." The AI that goes by the name of Friday greeted.

"So, after rescue Nat and finish off Ultron, you wanna go on a double date with me and Kairi?" Sora asked as he was swinging his Keyblade.

"Well... I got no plans for tomorrow..." Cap said while adjusting his suit.

"Well, Kairi and I are gonna see this musical that has something to do with cats." Sora said. Tony heard and shook his head.

"I get the first crack at the big guy. Iron Man's the one he's waiting for." Tony said"That's true, he hates you the most." Vision added as he walked by. Sora snickered making Tony glare at him. Meanwhile, Bruce was in near the doorway to a quinjet. He tells Betty to go with Fury.

"Look, after all of this is over. I promise we'll have a nice life together." He said to her. "We can leave the country and not have your father bug us. Betty smiled and crashed her lips onto his. Kairi and Elsa smiled as they walked with him. to the quinjet. Meanwhile, Cap was giving a speech.

"Ultron knows we're coming, odds are we'll be riding into heavy fire, and that's what we signed up for. But the people of Sokovia didn't. So, our priority is getting them out. All they want is to live their lives in peace, and that's not going to happen today. But we can do our best to protect them. And we can get the job done and find out what Ultron's been building. Keep the fight between us. Ultron thinks we're monsters and we're what's wrong with the world. This isn't just about beating him. It's about whether he's right."

While the others are gathering the people of Sokovia, Kairi, Elsa, and Bruce found Nat in a jail cell thanks to a tracker. Natasha in the cell is waiting in the cell. She was lying down staring at the ceiling waiting for someone to come rescue her.

"Nat!" She heard a familiar voice call out to her. She looks up and smiles to see Kairi, Elsa, and Bruce coming to her.

"Kairi, Bruce, Elsa. Thank God you're here. What's going on?" She asks.

"The team's in the city. It's about to lift up." Kairi said as she uses her Keyblade to unlock the door.

"So, what's our play?" Natasha asks.

"I'm here to get you than for me to safety," Bruce said heading for the exit.

"What about our team? The jobs not finished." Nat said.

"I can help people get to safety but I can't get into combat," Bruce said. Natasha frowns at him.

"So you just disappear?" She asked. After Nat's rescue, They started to head out.

Sora, Cap, and the others were gathering civilians out to avoid any casualties. Tony was in pursuit of Ultron. Friday has his location.

"Your man's in the church, boss. I think he's waiting for you." FRIDAY said.

Tony then lands his armor at the abandoned church. He sees Ultron.

Come to confess your sins?" Ultron asked.

"I don't know," Tony answered. "How much time you got?"

"More than you." Ultron quipped then he reveals his new armor.

"Um... have you been juicing?" Tony asked. "Little Vibranium cocktail? You're looking...I don't want to say puffy, but..."

"You're stalling. To protect the people."

"Well, that is the mission. Did you forget?" Tony asked.

"I've moved beyond your mission. I'm free." Suddenly, the floor broke apart, and a cylinder vibranium core, roughly two and a half feet high, exploded from the tile floor of the church. "What, you think you're the only one stalling?" Ultron sneered.

There's the rest of the Vibranium. Function: still unclear," FRIDAY reported.

"This is how you end, Tony. This is peace in my time," Ultron boomed. Abruptly over the ground, metal arms and hands darted away from underneath the streets that caused disarray in the city. Vehicles shrieked to a gnawing end as they steered to move away from the metal head that jumped out starting from the earliest stages. It seemed like a large number of metalheads pulled out of the trench-like bugs and flew up in the skies, shooting up in the sky with their blue energy made by Ultron himself.

A huge number of small-scale Ultron's zoomed noticeable all around bungling each other threatening individuals of Sokovia as they attempted to dodge for cover.

Tony heard the shouts and the ejections outside the Church and hopped up out of the Church, prepared to assist with killing them off.

"Go!" Cap shouted at everyone as they ran, heading for cover until one of the robots landed on a parked car and started to shoot energy beams at Cap. Cap ducked behind his Shield, and whacked him down on the ground in a heavy heap, knocking him out. Sora Shocks the Sentries with Lightning. He then beheads them with his Keyblade. Clint was shooting sentries one by one.

Clint began shooting his arrows at one sentry after another from behind while Wanda was attempting to direct the civilians to safety.

"Get off the Bridge!" Wanda said as Clint shoots his arrow at an Ultron Sentry and scores an immediate hit.

One Ultron Sentry was going to impact Wanda, yet she made a red energy safeguard with her forces and blasts them.

"RUN!" She urged the people.

Back inside the Church, Vision flew inside, gradually down to meet his producer. "Ultron," Vision said in a noticeable manner of speaking. Ultron flew vertically to compromise.

"My vision.," Ultron said.

"You set the terms, you can change them," Vision said. "Okay," Ultron said.

Ultron reacted by gagging the Vision. Nonetheless, this offered the android the chance to hack into Ultron's centralized computer and keep him from getting away through the net.

"Boss, it's working. He's burning Ultron out of the net. He won't escape through there." FRIDAY informs.

Vision successfully severed his connection.

"Ugh! You shut me out! You think I give it care?!" Ultron fights back and tosses down Vision. "You remove my reality, I remove yours."

Ultron activates the key, The Avengers felt the tremors around the city, just to discover the city is lifting.

Ultron flies and looks. "The magnificence of it. The inevitability. You rise just to fall. You, Avengers, you are my meteor. My swift and awful sword. Also, the Earth will break with the heaviness of your disappointment. Cleanse me from you computers! Turn my own flesh against me! It means nothing! When the dust settles, the solitary thing living in this world will be metal!"

Iron Man flies and looks.

"The vibranium core's got a magnetic field. That's what's keeping this rock together." FRIDAY relays information.

"If it drops?" Tony asks.

"Right now the impact would kill thousands. Once it gets high enough, global extinction." FRIDAY explains. Tony's heart nearly dropped. He flies by a building. He sees a family inside.

"Hi, okay." He said examines. where to put the family to safety. He sees a bathtub and has an idea.

"Get in the tub." He ordered.

He flies away from the collapsing building with them in their tub.

"I got airborne heading up the bridge!"

Back in the underground. Kairi and the others can hear the battle outside. Natasha turns to Bruce in concern.

"You gonna turn green?"

"I've got a compelling reason not to lose my cool," Bruce added. Natasha put her hand on Bruce's hand.

"You're a good friend." She then pushes him down then Bruce comes back as the Hulk. "But we need the big guy." Hulk smirked and carries her to the city with Kairi flying while Elsa was riding on her ice.

Back at the battle, Sora was killing off Sentries and Heartless. He sent a couple on firaga on another. Ultron sees that he destroyed his sentries and shakes his head..

"This won't do, Keyblade Master. I need the power of darkness to destroy you." With that, he snapped his fingers as Big Body Heartless came. Sora groaned.

"These guys are my least favorite Heartless." Sora closed his eyes before smirking. He jumped before the Large bodies could get to him. Making them bump into each other and causing them to be dizzy. He mastered his Sonic Blade and slices through the others. Once he took care of them, he rushes off to help the others. He sees his wife, Elsa, and Natasha joining the battle. Cap joins him after killing a sentry.

"Cap, Sora. You got incoming." Tony said from the commlinks.

"Incoming just already came in." Sora said. He sees an entry crash into a building. He looks up at his best man.

"Stark, you worry about bringing the city down safely. The rest of us have one job: tear these things apart. You get hurt, hurt 'em back. You get killed... walk it off."

The Heartless and the sentries continue to attack the civilians until the Hulk came and joined the fight. He smashed a couple of Sentries and disintegrating more heartless. Wanda is continuing to save more people while Clint is shooting more arrows. He shoots perfectly towards a sentry's head while Wanda was having a nervous breakdown.

"How could I let this happen?" She asked. Clint jumps down to comfort her.

"Hey, hey hey. You okay?" He asks her.

"This is our fault." She said referring to her and her brother. Clint puts his hands on her shoulders.

"Hey, look at me. It's your fault, it's everyone's fault, who cares? Are you up for this? Are you? Look I need to know, cause the city is flying." He was interrupted by a sentry who fired a shot through the wall. As he stood up, he aimed his bow through one of the newly created holes in the wall and fired it. He turns back to Wanda.

"But I'm going back out there because it's my job. Okay? And I can't do my job and babysit. Doesn't matter what you did, or what you were. If you go out there, you fight, and you fight to kill. Stay in here you're good, I'll send your brother to come find you, but if you step out that door, you are an Avenger."

Back at the city, Sora, Cap and Thor see three cars to fall from a broken bridge with a woman in one With no time to think, Sora jumped over to save them. Thor reaches it and grab the woman's hands and tosses her to Sora. Sora with all his strength pulls her up and tells her to run to safety.

"You can't save them all. You'll never…" Ultron's bot starts to say before Cap throws his shield into the bot and flinging it of the edge. "You'll never what? You didn't finish!"

Thor lands back on the bridge with the car with the two civilians in it. "What, were you napping?" Cap joked.

Natasha, Kairi, and Elsa join the fight dodging laser fires and taking down Ultron sentries. Kairi flew and used her plasma hands to destroy the sentries. Elsa jumps off of Kairi and throws ice at the sentries' hearts. She also freezes them making Kairi and Natasha destroy them in a single hit. Elsa creates a giant snowball then looks over to Sora.

"Hey, Sora." He looks at the queen. "Do you wanna push a snowball?" Sora smirked then tightened his Keyblade, using it to push the snowball into drones and causes them to malfunction. Kairi meanwhile was searching for civilians. She widens her eyes to see Sentries and Heartless surrounding a little girl. She growls in angel and flies to land in front of the little girl. She blasts them into pieces and destroyed a bunch of Heartless. She crouches down to the girl's level.

"I'm gonna help you find your parents, okay?" The little girl nodded.

"You're my favorite Avenger." She said. Kairi smiled in her helmet. She picks up the little girl as they search for her mother. She examined a bunch of people until she heard a woman yelling.

"Sarah!" The woman cried out. The little girl point to her.

"That's my mommy." She said. Kairi nodded and flies to the woman. She hands her to her mother and flies back to battle. Thor sends out the sentries with his hammer and killing more Heartless. Ultron growls in anger.

"Thor, you're bothering me." He said as he grabs Thor. Clint was shooting arrows at more sentries but they piled on him. Feeling encouraged by Clint's words, Wanda finally jumps into action by using her powers to destroy the sentries. Clint nodded at her.

"All right, we're clear." He said.

"We are not CLEAR!" Cap grunted as he punched a Sentry. "We are not very clear!"

"Alright, coming to you," Hawkeye called back. Meanwhile back at the church, Thor was still fighting Ultron while sentries were firing a blast at Police officers. Wanda and Pietro stood in their way. Wanda destroys the drones with her bolts while Pietro killed some with his speed. However, a police officer accidentally shoots him. Pietro ignored it and continued fighting. Sora, and Cap see Natasha struggling. Thinking clearly, Cap throws his shield to stop a sentry from hitting his fiance.

"Thanks, Babe." She said to her future husband as she kills a drone with her batons. Natasha then uses his shield to block a drone. She tosses it to Cap to make a final blow. Sora was killing some Heartless him. Suddenly a blast causes him to fall down. He looks up to see a Sentry approaching him.

"Sora!" Cap exclaimed as he throws his shield at Sora. He catches it and throws it at the drone before it could attack.

Pietro instantly sprinted to his sister, hoisted her in his arms, and carried her away. "Keep up, Old Man." He said to Clint. Sora kills a sentry then turns to his comlink.

Well, nothing great," Stark admitted. "Maybe a way to blow up the city. That will keep it from impacting the surface if you guys can get clear."

"We asked for a solution, not an escape plan," Cap told him.

"Impact radius is getting bigger every second. We're going to have to make a choice." Tony replied.

"Honey, these are people are going nowhere," Natasha said. "If Stark finds a way to blow this rock..."

"Not till everyone's safe." Cap interrupted.

"Everyone up versus down here?" Natasha questioned. "There's no math there," Natasha said.

"I'm not leaving this rock with one civilian on it." Cap said.

"I agree with Cap. We are not letting these people die." Sora said with a raised fist.

"I didn't say we should leave, Sora." Natasha said. "There are worst things to go." Sora looked at her in sadness. He and Kairi were planning to start a family. Natasha puts her hand on Sora's shoulder.

"Besides, where else are we gonna get a view like this?" The group was silent. At least until they heard a familiar voice: Nick Fury.

"Glad you like the view, Ms. Romanoff." Fury said. "It's about to get better." They all looked up to see him with Maria Hill and the rest of S.H.I.E.L.D arrive in a hellicarrier.

"Nice, right? Pulled her out of mothballs with a couple of old friends but she'll do." Fury told them. Cap gives a chuckle.

"Fury, you son of a bitch." Fury made a fake scoff.

"Ooh... you kiss your mother with that mouth?"

"Altitude is 18,000 and climbing." Said Hill while looking at her monitors

"Lifeboats secure to deploy." Replied Cameron Klien, a S.H.I.E.L.D. agent. "Disengage in three, two... take them out!" The helicarrier then Then deploys a group of lifeboats to rescue civilians. Elsa was amazed by this transportation vehicle.

"Wow... this is truly amazing." She said. Petro too, was impressed.

"That's S.H.I.E.L.D.?"

"That's what S.H.I.E.L.D.'s supposed to be." Sora replied. The transporters readies to retrieve the civilians.

"Let's load them up." Cap ordered.

"I'll help." A voice called out to them. Sora looked from behind to see Cloud jumping right beside him.

"Cloud What are you doing here?" Sora asked. Cloud gave him a smirk.

"I did it, I defeated Sephiroth." Sora's eyes widen.

"What?"

"Let me explain..."

And Cliffhanger. How did Cloud beat Sephiroth? We'll find out soon enough. Oh and Happy Sokai day everybody. First part of the next chapter is Sephiroth's death. Until then, enjoy this chapter. Take care.