Disclaimer: I do not own Marvel Cinematic Universe, Buffyverse or anything else you may recognize

Thank you to everyone who has favorited, followed or reviewed this fic so far.

Also, its hilarious how I forgot to mention this in like 26 chapters of 'The Spider, the Slayer and the Key', as well as the previous 3 chapters of this, but the suit Peter made for himself in this story is like the one from the Raimiverse.

Chapter 4- A brief history lesson

Los Angeles, Wolfram and Hart

Lindsey noticed the lawyers were all evacuating the place, running into elevators as he walked out to see Lilah. "What's going on?"

"You didn't hear?" She asked and he shook his head. "An alien warlord called Thanos has attacked Earth, he is trying to collect the Infinity Stones to wipe out half of all life."

"Oh! Those!" Lindsey scoffed. Their firm had records on the Stones.

Hunt Acrey then walked to them and said. "You two are the best we have. We're all leaving."

"Where?" Lindsey asked.

"Different dimension", Hunt told them as the three moved to the elevator together.

Sunnydale, Spike's crypt

The door opened as Buffy walked in, and Spike got up to look at her.

"Buffy, why are you here?" Spike asked before smirking. "Is it for-"

"No, it's important", Buffy said. "We have a war at our hands."

"Huh? And outside of me loving a fight, why should I care?" Spike asked as he walked to her.

"Half of all life will be destroyed if we lose this one", Buffy said, but Spike didn't really react to it.

"Well then, less food for me in that case", Spike then quipped, walking off to get his leather duster, and put it on. "Come on."

Buffy sighed in relief that he had agreed to come, and they went out together as Spike put a blanket on himself.

Parker house

"Peter, if this is even half as dangerous as Giles is saying, maybe-" May trailed off as Peter sighed.

"I know you worry, Aunt May, and I get it", Peter assured her, his suit now on. "But I have to go, and you know why."

May sighed, not liking it one bit, but also knowing she couldn't stop her boy from trying to save the world, because that clearly defined him as much as his passion for science.

"All right", May said as they shared a tight, loving hug, and she kissed his forehead a few times. "But please, be careful, please."

"I will", Peter assured her with a nod.

Later, Magic Box

Peter walked in as he saw Buffy was holding the Troll Hammer and Spike was already there. "What's up, bug boy?"

"Going to save the world", Peter told him.

"I'm just going in for the fight", Spike smirked as Peter sighed.

"You tried that Angel guy?" Peter asked Willow.

"He isn't picking up, and no one else from his team is either", Willow told him grimly, as Buffy wondered what the reason for that could be.

"So I guess it's all of us then", Tara said, gesturing to them all.

Buffy turned to Xander, Dawn and Anya. "No matter what happens, you three are staying inside the castle, or whatever it is."

"Yeah, I get it, don't wanna be a hindrance", Xander said with a nod. "Though I'll still keep a gun."

"If I had my powers, I could have erased them all with a wish", Anya muttered. "I'll stay though."

"Yeah, me too, though I will keep a sword just in case", Dawn added.

"Good", Buffy nodded.

"I believe it is time for all of us to go now", Giles said he closed his eyes and chanted, and then all of them disappeared from the Magic Box in a flash of light.

Avengers Compound

The Scoobies all appeared near the Quinjet, Spike still holding onto his blanket tightly as Steve noted. "Good to see you all again."

"We're teaming up with the Avengers again!" Xander said excitedly.

"It's not going to be a cakewalk this time, bub", Logan warned him.

"Yeah, we get it", Dawn said, her fangirl much less excited this time due to what the stakes were, of course last time she herself was the stake but her fangirling had been done before she'd been captured, so there was that too.

"So, we ready to go then?" Buffy asked.

"Yeah", Steve nodded as they all walked into the Quinjet, and it closed, before flying off.

Later

Sam flew them towards the destination with Clint in the co-pilot seat, and Dawn and Anya, who had never been inside one before, looked around at all the controls in awe and Dawn asked Peter. "Can you drive this?"

"Theoretically, yeah, but actually doing something is different from knowing how to do it", Peter told her, the two sharing a smile at that.

"Hey Cap, we're coming up on it", Sam then spoke up.

Steve nodded as he got out of his seat and walked to the controls.

"Drop to 2600, heading 030", Steve ordered the two.

"Hope you're right about this, otherwise we're gonna land a lot faster than you want to", Sam muttered as he and Clint followed orders.

"Oh he is right about this", Clint said with narrowed eyes.

The Quinjet then flew lower, passing the barrier that hid Wakanda from the outside world as Spike muttered. "Blimey! That was something!"

"This barrier must be real advanced", Willow noted with awe. "If I get the time, I'll have to study it."

"Get in line", Bruce muttered to her.

The Scoobies, Logan, Rhodes and Bruce looked around the city in awe as Sam flew the Quinjet to the palace, where T'Challa and his guards, including the Dora Milaje, were waiting, as well as Clint's family, who Natasha and Fury had gotten out in time after Tony had run his mouth, and now they had been settled in Wakanda.

Sam brought the Quinjet down and lowered the ramp as Spike spoke up. "Vampire here, can't walk out in sunlight."

"We actually talked to him about this before coming, the barrier doesn't exactly block sunlight, but it blocks the specific components in sunlight that are harmful to Vampires", Natasha informed Spike.

"Huh? Really?" Spike asked as he walked to the edge and poked his hand out, and, to his delight, it wasn't burning up. "I love this place!"

"I have to find out how it does that", Peter said to himself.

Spike then walked out, raising his hands and basking in the sunlight, as the rest rolled their eyes and followed after him.

The children ran to Clint and Natasha at that moment.

"Daddy!" Nate said as Clint happily lifted him up, "Hey champ!"

"Auntie Nat!" Lila hugged Natasha who kissed her forehead happily while Clint patted Cooper's head.

"Hey Hawkeye." Laura said as she and Clint kissed.

"Honey." Clint simply smiled.

"Should we bow?" Bruce asked.

"Yeah, he's a King." Rhodes told him.

"Seems like I'm always thanking you for something." Steve said as he shook hands with T'Challa.

"Thank you for having us again", Bucky added from where he was standing.

Bruce coughed and bowed to T'Challa.

"What are you doing?" Rhodes then asked as he looked embarrassed.

"Uh, we don't do that here." T'Challa told him as Rhodes gave him a 'gotcha' look.

"So this is where they will come." Buffy said as she looked around.

"Yeah, bub." Logan said.

"This is the first time a Slayer has stepped foot in Wakanda since Bashenga's grandmother", T'Challa commented as he looked at Spike. "And the first time for a Vampire."

"Wait what? Who's Bashenga?" Buffy asked.

"The first Black Panther", T'Challa commented as they walked together. "We here know everything about Slayers and the Watcher's Council, I just did not mention it last time we met."

"How do you know all that?" Tara asked.

"Like I said, Bashenga's grandmother was a Slayer, the First one", T'Challa revealed, to the shock of the Scoobies, other than Peter and Spike, who hadn't been kept in the loop about that.

"Sineya", Buffy whispered in realization.

"She had a child when young before what was done to her", T'Challa said sadly. "When her grandson found Wakanda, he vowed to make sure no other Wakandan woman would be forced to be called as a Slayer."

"How did that happen?" Willow wondered.

"The power of Bast the Panther Goddess protects the women of Wakanda from being made a Potential", T'Challa revealed to them all as he looked at Giles. "We keep watch on the Council as well, every move of theirs."

"Well, if it's any consolation, we aren't big fans either, on my 18th birthday they took away my powers and put me in a dangerous test", Buffy told him. "Though recently we got allied with them again but on my terms."

"Our deepest condolences for what happened to Sineya", Giles assured T'Challa.

"We do not hold grudges for the sins of the ancestors anymore", T'Challa assured Buffy and Giles back in return as they sighed in relief.

"Interesting history lesson", Willow muttered.

"Yeah", Tara nodded.

As they walked further, T'Challa finally asked the important question. "So how big of an assault should we expect?"

"Uh, sir, I think you should expect quite a big assault." Bruce said.

"How we looking?" Steve asked.

"You will have my Kingsguard, the Border Tribe and the Dora Milaje." T'Challa said.

"I'm not sure that will be enough", Bruce said uneasily.

"It has to be!" Buffy said, not wanting her dream to come true.

Steve turned to Logan, Bucky, Sam and Rhodes. "Set a perimeter with the guards, the rest of us will go inside."

"I am staying outside", Spike said as he raised his hands and basked in the sunlight again with a smirk.

All rolled their eyes again as Steve and Buffy said simultaneously. "Fine."

They walked inside to see T'Challa's sister Shuri waiting for them.

"When the world's not ending, I want a tour of this place", Peter said.

"I think you'll annoy him", Dawn told Peter.

"I will be pleased to give you one after this", Shuri told Peter as Vision got onto the table and Shuri began scanning him.

Shuri then opened her palm, shocking everyone with the holographic display in her hand as Peter muttered. "Whoa!"

"The structure is polymorphic", Shuri said.

"Right, we had to attach each neuron non-sequentially." Bruce told her.

"Why didn't you just reprogram the synapses to work collectively?" She asked.

"Because we didn't think of it." Bruce said lamely.

"I'm sure you did your best." Shuri said with the arrogance of a teenager.

"Can you do it?" Wanda asked her.

"Yes, but there are more than two trillion neurons here." Shuri said. "One misalignment could cause a cascade of circuit failures."

Shuri turned to her brother, "It will take time, brother."

"How long?" Steve asked.

"As long as you can give me." She said.

"We will give you as long as you need", Buffy assured Shuri.

Peter and Dawn were holding hands when suddenly Peter felt the hair on his hand stand up and she noticed it too. "Pete."

"Oh boy", Peter said as he realized what was going on. "I think they're here."

Then the alarm beeped as Okoye activated her beads.

"Something's entered the atmosphere." She reported.

"Our enemies." Giles said in realization. "Thanos' army."

Spike, Sam, Bucky, Logan and Rhodes stood outside.

"Hey, Cap, we got a situation here." Sam said as a dropship crashed on the barrier and exploded into pieces.

"Pop goes the weasel." Spike joked.

"God, I love this place." Bucky groaned.

"Oh anyone would, bub." Logan told him.

"I love it so much because I can bask in the sun all I want", Spike said as he raised his hands and basked in sunlight again.

"Yeah, don't start celebrating yet, guys." Rhodes said, "We got more incoming outside the dome."

Several other dropships fell outside the barrier.

"It's too late." Vision said as he staggered up, "We need to destroy the Stone now."

"Vision, get your ass back on the table." Natasha told him as she walked out.

"We will hold them off." T'Challa said as he walked with his army.

"Wanda, as soon as that Stone's out of his head...you blow it to hell." Steve ordered Wanda.

"I will." She said.

"Since we're staying, we can help guard Vision." Xander told Wanda and she nodded in appreciation.

"No worries", Dawn smiled.

"Are we really supposed to stay?" Anya asked and was shot looks. "Right!"

"Evacuate the city." T'Challa ordered everyone. "Engage all defenses."

He then turned to Steve, "And get this man a shield."

Steve nodded firmly.

"Our strongest foes so far", Willow comment.

"Strong is fighting", Buffy quipped as they moved out.

Peter and Dawn shared a kiss as Dawn requested. "Please be careful."

"It's they who need to be careful", Peter said with a smile as she chuckled and they kissed again before he walked out, the two sharing one last look with each other.

Next chapter is gonna be all of the big fights from IW.

Thank you to Brainstorm Sorcerer for the suggestion with Bashenga and Sineya.

Hope all enjoyed and see you all next time with another chapter. Stay safe from the coronavirus ya all!