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.

And thanks to Brainstorm Sorcerer for some scene help too, like always.

Guest: Thanks for the review and think you got it right on all the Spider-Man and Superman actors.

Chapter 4- Knowing Thy Enemy

Strange was watching the Orb of Agamotto, as scenes of the Avengers, Scoobies, Team Angel, SHIELD Team, X-Men, Defenders and other heroes helping with natural disasters were happening across the world, and only increasing in intensity.

It was terrible. They were trying their best to save lives but it was quite hard due to the magnitude, plus the quantity since these were occurring almost everywhere.

Wong appeared at his side, having portaled in from China, "Things are getting worse."

"I know."

"Hong Kong is plagued by earthquakes-"

"I know."

"Half of Europe is almost flooded-"

"I know!"

"And we have fire raining down on-"

"I KNOW!" Strange shouted at his friend, causing him and the nearby Sorcerers to recoil at the sudden exclamation.

Strange breathed in and apologized. "I'm sorry, its just, these disasters are messing up my mind."

He then focused on the Orb, showing the Earth, but covered in a dark blue, violet sort of aura. "I can't identify what's causing this, or even how it started! Every time I come close to an answer, to what's causing all this, I find a dead end." Strange was still in top form, so someone was blocking his attempts to find out.

And that someone was very powerful and skilled if he could block the Sorcerer Supreme of all people

Stick then appeared. "I've seen some crazy shit in my day, but this is taking the cake." He stood at Strange's side, looking at the Sorcerer Supreme, hoping to get some answers.

"To stop this we need answers, otherwise we're looking at an apocalypse."

Suddenly a ghostly figure went by them, one they all recognized.

"Ah, great to see you here", Stick called out to the ghost of the Ancient One but got no response. "Hey, I was talking to you."

"Master!" Wong called out to her but still no reply.

"I believe she wants to show us something", Strange realized as the three followed her while she ignored them, until they made they make it to the library. "What is it?" He asked as she continued walking.

They followed her until they made it to a particular shelf, then she disappeared from view.

Wong knew the library well, and Stephen had memorized it, so they saw something out of place as the former said. "That book detailing the origins of ancient languages and foundations of magic is in the wrong place. These books hold no valued secrets, no hidden messages."

"Yet I've never seen them moved from these spots."

Wong realized that too. "Neither have I."

Strange reached his hand forward and it disappeared, he pulled it back and it was fine, then he moved forward into the bookshelf, and ended up in a small chamber.

A portal of sorts!

"Thank you", he said to his absent mentor, looking at the room which seemed blank with one source of light coming from the ceiling, and a large yet thin book at the center.

"It cannot be." Wong whispered in awe, having walked in after Strange. "The Chronicles of the Sorcerer Supreme."

"I thought that was a myth."

"So did I."

"Would someone like to inform the non-mystically inclined?" Stick spoke up after having walked in himself, clearly annoyed.

"The Chronicle is said to contain the histories and lives of every Sorcerer Supreme that's came before, even their secrets."

With that, Strange opened it as Wong and Stick read it next to him.

What they found out shook them to their core.

"We need to gather the rest and tell them all of this quickly."

A while later, Strange had managed to gather Steve, Thor, Tony, Bruce, Natasha, Clint, Bucky, Sam, Wanda, Peter, Matt, Logan, Buffy, Spike, Willow, Tara, Dawn, Giles, Felicia, Angel, Cordelia, Faith, Wesley, Lilah and Illyria together at Avengers Tower while the rest were still helping with the disasters all over the world.

"So you know who is behind this then?" Peter asked and Strange gave a nod.

"Well, tell us, we're listening", Lilah sat down to listen to him.

"More than a thousand years ago, Earth was besieged by an entity from outside the multiverse. Called a Great Old One, Many-Angled One, Dark One, no one knew what it really was, except it came here, to conquer or destroy, not sure."

"I have heard of it before", Illyria spoke as they turned to her. "They were greater Old Ones than we were, while we came to Earth, they lived in their Dimensions. Their power was great."

"You saying that the world going bonkers is because of this bloke with too many names?" Spike then asked Strange after giving Illyria a nod at her info.

"Shuma-Gorath, and no, this is not it's doing, not exactly. It was opposed by the Sorcerer Supreme of that time: Merlyn."

"He's real?" Dawn inquired, the jaws of all but Thor dropping at that point.

Strange nodded and continued telling them everything he knew.

"He was, and a hero, according to the chronicle. Once Shuma-Gorath came though, Merlyn was helpless. This thing was devastatingly powerful, Merlyn alone couldn't stop it, nor was there anyone he knew that could aid him. So, he made a desperate gamble." Strange looked directly at Matt, who could feel his eyes and the eyes of everyone else turning to him. "He made a deal with the Devil."

Matt's face turned to one of stunned shock, before he growled the name, with Adam's voice overlapping his.

"Mephisto."

Faith held his hand as they continued listening what Strange was saying.

"Merlyn asked for the power to save the Earth, and Mephisto granted it. With his new, hellish power, Merlyn was just barely able to push Shuma-Gorath back to it's own dimension, and seal the tear it came from so no more of its kind could get through…and it all went wrong from there."

"This is Merlyn's doing?" Steve asked, shocked, sharing looks with the rest of them.

Strange looked grim and regretful now.

"Yes, but I don't know how. The chronicle details every moment of the Sorcerer Supreme since they are bestowed the position, but after Shuma-Gorath's attempted invasion, there's no more about him, it was a hundred years before the next one appeared, and after them came the Ancient One. Whatever Merlyn did, stripped him of his duties of Sorcerer Supreme."

"He wanted to protect reality." Everyone turned to the new voice, one Angel and Spike recognized and started groaning since they knew who it was, as Hercules aka the Immortal walked in, wearing a new suit of dark green and gold that exposed his biceps. "And he damned himself to do it."

Angel and Spike pushed their women behind them, making everyone roll their eyes. Despite the fact he was their friend now, the Vampires clearly couldn't let go of their hate for the guy.

"So, you know some more eh Herc?" Tony asked and got a nod from Hercules.

"Please, we would love to know all", Giles gestured to him to tell them whatever he knew.

"You knew Merlyn?" Strange then asked.

"I knew him when he was called Myraddin, born and raised on Ruta, one of the Atlantean islands that survived the cataclysm."

"Atlantis is real?!" Buffy asked, jaws dropping again at the info.

"Well I'll be damned", Sam muttered.

"So will we all", Wesley said, sharing a look with Giles.

But Hercules didn't answer Buffy's question, instead, his expression became melancholic.

"Something horrible happened, didn't it?" Natasha asked Hercules who nodded.

"He was my friend. Wise, humble, compassionate, he was the everything great about humanity…until he made that accursed deal with Mephisto. Merlyn knew what the consequences of associating with that Devil, but desperation makes fools of us all." A moment of silence where the people were all reflecting on what Hercules said, and their own desperate times. "Once Shuma-Gorath was pushed out of our universe, Merlyn began to change, physically, and mentally. He talked of protecting everyone, this whole universe, before there was another threat like Shuma-Gorath again. Only, Merlyn's talk of protection turned to paranoia, where everyone except himself was a threat to reality, he even threatened to finish the job Hera started when I was a baby."

"If Merlyn was so kind before, how could he do that?" Willow asked, though she was beginning to have an idea.

Hercules' face turned into a snarl. "It was Mephisto's fault. By giving Merlyn the power of Hell, it overwhelmed him, corrupted him like a poison. Soon enough, he made his move to turn himself into the ultimate power, by taking everyone else's away. All for the sake of "protection", but he was so lost that he never realized all he sought to accomplish was destruction."

"How was he stopped? It sounds like Merlyn was invincible." Tara noted.

"That he was, every second that passed, Merlyn only grew stronger. It took an alliance of good and evil to finally put him down. My father, your father," he looked to a surprised Thor, "pantheons, sorcerers, heroes of old, demons, Hell Lords, myself, even Mephisto." Matt showed his shock with a dropped jaw. "Seeing what he created, Mephisto had no choice but to help. Merlyn, however, relished in the challenge, he thought by fighting the obstacles sooner, his task would be completed at a faster pace. His arrogance worked against him, yet Merlyn proved why he was Sorcerer Supreme in the first place. The battle went on for weeks, the destruction…I have never seen it's like before in all my years, not until the Snap. By the end, there was no clear winner, and Merlyn was regaining his strength. We had no option but to contain him, a tomb that would drain Merlyn of his power to trap himself. Before he was lost to the ages, Merlyn had vowed revenge on those who opposed him and would return to complete the mission he started, but first, he abandoned the name that once portrayed "weakness"."

Hercules sighed as a tear escaped him, the pain inflicted at recalling the story truly affected him, but they realized that living as long as he has, Herc would have lost many friends. This time, the demigod lost one to evil.

"He had dubbed himself…Apocalypse."

"Apocalypse?" Thor repeated in surprise.

"You know the name, Thunderer?"

"I do, yet I have not heard it for an age. I was only two hundred years old."

Tony turned to Cap and then mouthed in surprise "only?" but Steve waved him and turned to focus on the God.

"I was feasting with some mortal worshippers, when a scout warned us of a Jotunns attacking. I grabbed my axe, Jarnbjorn, I hadn't earned Mjolnir yet," he explained to those with confused faces, "and what I saw was no Jotunn. It was stronger than any Giant, it nearly overpowered me, had I not blessed Jarnbjorn with my blood and used it to cut through Apocalypse's defences, I doubt I would have survived the day unaided. Then, he was gone like a leaf on the wind, no trace, no explanation. When I asked my father of it, he denied me an answer."

"But wait, wouldn't he be contained at the time?" Cordelia then asked.

Hercules now showed his horror filled expression as he realized the implications. "The tomb, it was supposed to be secure. Everyone who aided in stopping Apocalypse made a vow to never utter his name, so he would be forgotten by all in time. But if he appeared in Norway, then he found a way to bypass the protective magics."

"Which means Apocalypse could have orchestrated his escape." Strange summarized.

"Even if Apocalypse did find such a fool, it would take a tremendous amount of energy to break the tomb open. Such a source would have been noticed." Angel pointed out to them.

"It can't be the Stones." Logan vetoed that already.

"My satellites monitor for any outstanding anomalies." Tony added.

"Where could that energy have come from?" Clint then wondered.

"Is there any, lightly defended yet still potent source of power that someone could have sneaked into and taken for themselves to raise evil wizard from his grave?" Bucky wondered out loud for the rest to think.

"Still new so no idea, sorry", Felicia sighed.

"Well then, let's all think", Faith told them all.

Angel then got recognition on his as he thought further. "The Deeper Well."

"Where Blue Meanie was?" Spike asked as Illyria shot him a look but he didn't care.

Angel himself couldn't believe it and his face was of disbelief. "Drogyn is a fierce warrior, I find it really, really hard to believe someone could have gotten past him."

"Still, it is one lead", Wanda pointed out.

"So let's run it down", Bruce agreed.

"Yeah, seems like our best shot", Buffy nodded.

"In that case", Strange portaled to the entrance, and both Vampires as well as Matt sniffed blood, the Vamps running through as the rest followed.

"Oh no!" Angel crouched to Drogyn's body, his throat torn out. "Drogyn…..no."

Spike looked down sadly, Matt and Faith putting a hand on each shoulder of Angel while Cordelia crouched near him as Tara said in sympathy. "I'm so sorry."

"Which means…." Steve trailed off as they rushed into the Deeper Well, and found all the Old One sarcophagus' gone, since the loss of their essences had slowly decayed them right there.

"NO!" Illyria screamed, falling to her knees. "They were all…All of them are gone! My world is gone!"

She seemed completely broken apart, even worse than when she had discovered her army's fate. The Old Ones had no love lost for each other but they would have been a reminder to Illyria of her time.

And now they were gone just like that.

Steve knelt down next to Illyria. "I'm sorry, I know how you-"

"YOU COULD NEVER!" Illyria snapped at him.

"But I do, I too woke up in a time where all I loved except Bucky and Peggy were gone", Steve told her with kindness and understanding, taking her face in his hands and making her face him. "You do not deserve this, but I'll help you get through this. I promise you I will, and we'll make who did this pay."

"Damn right we will!" Angel snarled, thinking about Drogyn's corpse.

"Guess some idiot really did want the Wizard out", Spike scoffed.

Steve helped Illyria stand up, supporting her against him due to how broken she seemed to be now.

Hercules' horror was only increasing as he looked at the now empty Deeper Well. "By the Gods."

"You beat him before; we can do it again. We hit him until he can't take it anymore." Steve said firmly.

"Captain, I admire your optimism, but you fight a terror that scared even the Gods and Hell Lords. If he has been freed for so long, and his Horsemen are chosen, I don't even know if Apocalypse can be beaten now."

"Well, we know what happened, let's go back", Strange sighed as they went through the portal back to the Tower, Strange closing it as well.

"At least we know about the enemy now", Faith commented as Cordelia rubbed Angel's back while Steve wrapped an arm around Illyria, trying to comfort her, and she was letting him.

Meanwhile, on the wall, unseen, was a "locust" made of purple psionic energy, magic hiding it from all of their senses.

And on the other side, in Apocalypse's pyramid base, was Pestilence, smiling wickedly.

So we're done here, and now we know this Apocalypse's backstory. This is why he has the Mystic look instead of the Celestial one, due to the Merlyn/Sorcerer Supreme thing.

The Merlin/Mephisto backstory was inspired by Stand with Ward and Queen's 'Apocalypse on infinite earths' so thank you to him, but Brainstorm helped me modify it and make it different for this one, so thank you to him as well.

Poor Illyria, but I think the scenes with her and Steve managed to be surprisingly sweet if sad.

The babies, puppy and kitten are being looked after by the non-fighters on another floor, okay? Okay.

Hope all enjoyed and see you all next time with another chapter.