Disclaimer: Buffy and all related material is owned by Joss Whedon and Mutant Enemy. Desmond Miles and all related material are owned by Ubisoft. Just to be on the safe side if you recognize anything in this fic other than the plot than it is owned by somebody else. This is a not for profit fanfic. Please don't sue, I'm broke.

Pairings: Xander/Faith

Rating: I'm gonna go with M just in case. There will be gratuitous violence and bad language. Maybe some sexual situation but nothing explicit.

AN: I'm swapping two episodes from Season 2. Lizard Boy (S02E05) and Go Fish (S02E20), so that the swim team episode took place before the Halloween episode. The only other alteration to the world's timeline is I'm making Assassin's Creed the video games came out for the original Playstation which I think was available back in '98.

AN: Dawn isn't the Key, she is the biological sister of Buffy and the daughter of Joyce and Hank Summers. In cannon she is 2 years younger than Buffy which means that she will be a Freshman at the start of this fic.

AN: Fair warning there will be character deaths and bashing of several major characters, specifically Buffy, Willow, Angel, and Spike. No, I won't be killing all of them…I don't think. We'll see. If you like any of these characters you might want to go read a different fic.

Chapter 1

"I need coffee," Xander commented as he made his way blearily into the high school library where he and his friends usually met up to discuss whatever crisis was occurring that week. Pausing at the foot of the long table that took up the center of the room, he briefly debated whether to plop down in his favorite chair and be blinded but with a comfortable backside or grab a different seat and be uncomfortable but with the ability to see. After a brief pause the lanky teen came to a decision and sat with his back facing the windows where the god-awful daylight was cheerfully beaming in. After a huge yawn, he continued. "I'm gonna take a stand here and say that any time before noon on a Saturday is not of the good…Somebody remind me why I had to be here at 8 o'clock in the morning?"

"Because last night was major hellmouthy badness?" Buffy Summers suggested, as she looked at him with a perky blonde earnestness that only she could achieve. Fighting back a yawn of her own as she shrugged. "If I ever see that creep again I'm gonna introduce him to my foot. Although at least the French test on Monday is gonna be a breeze. Maybe I should thank him before I beat him up?" The Slayer shot a questioning look at Willow Rosenberg as her red headed friend came through the library's door and made her way to join the other teens at the table.

"Sounds fair to me Buffy." The red headed hacker/budding witch said as she took a seat next to her blonde friend. Looking over at her childhood best friend across the table she continued, "What are we talking about?"

"Why we're here at oh my god in the morning on a Saturday." Her yellow crayon buddy replied. "Speaking of, congrats on sleeping in Wills. I didn't know you had it in you."

"Yeah, there's just something about coming back from the dead that really takes it out of you. I've never slept so well."

"Morning everybody. Good morning English." Jenny Calendar said with a smile as she breezed in, her long skirt swirling around ankles. The attractive techno-pagan had just sat down next to Xander when the library office door opened.

"Yes well…Good morning." Rupert Giles responded as he came out of his office. Straightening his sport coat in a subconscious effort to impress when he noticed the beautiful computer teacher sitting with the group that Xander had dubbed the 'Scoobies', he moved to stand at the foot of the long table that dominated the ground level of his domain.

"I see that everyone made it home safely after the events of last evening." He commented as he met the gaze of everyone at the table. "Now that the circumstances of last night have been resolved are there any causes for concern that any of you have noticed? Any lasting effects for instance." The high school librarian and official Watcher for the Slayer looked around the table again, paying special attention to Buffy and Xander as he tried to ascertain if there would be any long term ramifications for Ethan Rayne chaos spell from the night before.

As usual, it was the Slayer herself who spoke up first, exhibiting the typical impatience he had come to anticipate from her. "I haven't noticed any Giles. Well except like I said, I'm down with the French now. I also have an annoying urge to do needlework and crochet. Ooh and the harpsichord. I can now play the harpsichord. Do harpsichords still exist?"

"Yes fascinating." Giles commented, choosing not to respond to the harpsichord comment of his charge.

"Ah phooey! I didn't get to keep anything. I wish I hadn't dressed up as a ghost. I always miss out on the good stuff." Willow pouted.

"Incidentally Willow, if you hadn't been a ghost, I wouldn't have known what was going on and last night might have turned out far more tragically. As the young red head visibly perked up at his statement, the librarian turned his attention to the dark haired young man on his right as he asked. "Xander, can I presume that you kept some vestiges of your possessor as well?"

"I had a quiet night at home. I take it something mystical happened?" Interrupted Jenny, as she unconsciously tucked a strand of her dark hair out of her face and behind her ear. The young Gypsy continued. "Somebody want to fill me in?"

"A man named Ethan Rayne opened a costume shop called originally enough Ethan's here in town recently." The middle aged librarian and her prospective boyfriend answered. "He cast a spell last night with the aid of the Roman god Janus to transform everyone who purchased a costume from him into that costume."

"My God!" Jenny exclaimed. "That's insane!"

"Quite." Was the Englishman's reply. Before turning back to Xander and continuing. "Xander, do you still have any remnants from your possessor? And who exactly were you dressed as?"

"I think so G-man. I mean I can remember the training but I doubt I have his skills. I probably remember some languages too." Xander replied.

"Who did you go as Xand?" Buffy asked. "All you'd say was that he was a character from a video game." Looking over at Willow she continued. "Did you recognize him?"

"Yes Xander, who was your possessor last night and what skills and languages are you referring to? And would you please refrain from that infernal nickname." Giles quickly followed before the shy teen could reply.

"I was dressed as Desmond Miles." Xander answered Buffy.

"Eeep!" Willow exclaimed. "Xanderhewasanassassin! Whywouldyoudressupashim?"

Although he was concentrating on the three people in front of him, Xander didn't fail to notice when his computer teacher's face whipped around to stare at him in shock at his answer.

After taking a moment to process the Willowspeak, Giles looked back at the lanky young teen and asked. "Your Halloween costume was an assassin?"

"I dressed up as a character from a video game series called Assassin's Creed. He was Jesse's favorite character Willow. Or have you forgotten?" Xander harshly asked. Referring to their childhood best friend/musketeer who was turned into a vampire shortly after Buffy came to town the previous school year. With his only remaining childhood friend visibly chastened he continued. "I figured this would be a good way to remember him. Besides it's not like I knew your old college buddy was gonna turn everybody in town into their costumes as a prank Giles!"

"Yes quite. Well as I'm unfamiliar with the games and character in question, perhaps someone would like to fill me in?" The Englishman enquired.

"What he said." Buffy chimed in. "I've never been into video games. I've heard of the game, my ex-boyfriend Pike back in L.A. was into it, but I don't know anything about it."

"Pike? Really? What is it with you and guys with one name Buff?" Xander asked incredulously as he tried to deflect everyone's attention from the subject.

"Shut up Xand. We're talking about you here." She shot right back and stuck out her tongue to taunt him.

"Right well, Desmond Miles was a hereditary member of the Assassin Order, Giles. They were known by various names throughout history, for example in the Roman Empire they were the Liberalis Circulum and during the Crusades they were the Hashshashin. They were the sworn enemies of the Templars. In the game, the Knights Templar wanted to save humanity from itself by imposing their own order on the people, creating a unified world order with them at the top, and since individual opinions lead to disagreement, and disagreement was contrary to order…well then the people would just have to not be allowed their own opinions. Basically they wanted to strip the free will from everyone not a member of the Templars. The Assassins on the other hand fought for individuality and the freedom to allow for growth and progress. So whenever a person or group began to gain too much power, become too despotic, the Brotherhood would step in and remove the leadership. This allowed for the progress of new ideas and a reason for the growth of a culture or civilization."

"I see." Giles commented. Taking off his glasses he began to polish them vigorously with a handkerchief taken from his jacket pocket as he continued. "And this Desmond Miles, he was an assassin in this…Brotherhood?"

Taking on a pensive look, Xander answered. "Not really. He was raised to be an Assassin but when he was a teen he ran away. He didn't want to be a killer. He also never bought into the whole Templar propaganda. Plus he was never very good at it anyway. He spent his days as a bartender."

No one but Xander noticed the incredulous look on Ms. Calendar's face as he explained the character of his possessor.

"But I thought he was the main character of the game?" Willow jumped in.

"Yeah, why dress as a guy that isn't any good in a fight?" Buffy asked.

Shooting a glance to Ms. Calendar as she shifted in her chair, as if about to comment Xander continued. "He was the main character, but in the game he was kidnapped by the Templars and inserted into a machine called the animus. What the machine did was make Desmond relive the genetic memories of his ancestors. For the first game it was a Syrian Assassin during the Third Crusade. In the game you played as him not Desmond."

"I see. So you don't have the skills of the Brotherhood then?" Asked Giles.

Turning his head slightly to face back towards the others, he kept his computer teacher in view as Xander replied. "Desmond only had basic assassin training, mostly stealth and firearms. But like I said, he ran away at 16 and never finished his training. And even if I did have clear memories of the full Assassin training regimen, it wouldn't matter since I don't have the muscle memory or conditioning to use any of it. Mostly I just got some language skills. I'm fluent in Spanish and French now. At least, I think I am. I'm also a pretty awesome bartender…but that's about it."

"Very well then, I will expect your French grade to improve accordingly Xander." Giles commented. "Do any of you know of any others that were altered by their costumes?"

"Cordelia was dressed as some kind of seductress. I'm not really what she turned into, but I saw her buying her costume when we were at Ethan's. She was complaining about how Party Town had sold her costume and she ended up having to slum it at a trashy little start up of a store." Buffy commented. "I don't think we ran into her last night, but she was supposed to go to some party at the mayor's so she was probably safe enough last night."

"I don't think anybody who transformed knows anything about the nightlife so we're probably safe that everybody'll just repress and continue on with their lives. Well except for Cordelia, and we can discuss her possession on Monday when she comes back to school." Xander said as the meeting began to wind down.

"Excellent. In that case please everyone keep an eye out for any after effects and come to me if there are any problems. For now I suggest that we try to put this experience behind us and continue on." Giles said before continuing. "Buffy since you are already here why don't we get your workout done now and that will give you the rest of the day to yourself…well, until you patrol tonight."

"I'm gonna go with…but I don't wanna!" The blonde former cheerleader whined, before continuing. "But I suppose having the rest of the day is bribe enough to get this stuff knocked out."

"Excellent. I'll just head into my office and grab my pads and we'll get started." Her Watcher replied as he moved towards the door situated behind Xander and Ms. Calendar.

"Cool, there's some stuff on the 'net I want to check out. I'll just hang here while you beat up Giles and then we can go grab some lunch." Willow said to her best female friend. "Xan, you up for hangin with me while we wait for Buffy?"

"Nah, I gotta meet up with Uncle Rory and take care of some stuff. Call me later?" Xander asked as he shot a significant glance at his computer teacher while standing up.

"Rupert, I've got some things to take care of as well." Jenny said to her fellow adult before continuing. "Maybe we can meet up this evening and talk?"

"I would like that." Her paramour replied as he walked out of his office minus the sport coat and with the addition of several heavy duty protective pads covering his torso, head, and hands.

Xander and Jenny didn't look at each other until after they'd cleared the library doors and walked down the hallway several yards. "Alright Xander, what did you leave out exactly." The young teacher asked her student.

The cheerful expression that she'd grown accustomed to seeing on her young students face fell away like a mask as his eyes hardened. While taking on a look of deep thought, Xander paused before replying. "O.K., before I answer that I need you to answer a question for me and I need you to promise that you won't lie or try to evade. This is REALLY important Ms. Calendar."

As her pretty face took on a curious expression she responded as they turned down another hallway. "Alright, shoot."

"Are you a member of the Gypsy tribe that cursed Angel?" He asked as he shot her a pointed look.

Stopping abruptly in the middle of the hall she exclaimed. "How did you know that?"

"Dammit!" He cursed.

The young computer expert and member of a notorious Romani clan listened in amazement as her young student continued cursing in at least three languages as they continued down the new hallway before continuing.

"Come on this is going to take awhile." He said as he led the way towards the computer science room before continuing.

"I know because Desmond knew. He was a fan of a TV Show called Buffy the Vampire Slayer." He answered before continuing. "Remember, the video games take place in 2012 and in the late '90s through to '03 there was a TV show about us in his reality. Buffy, Willow, Giles, you, me, and Angel among others, we were all in it. My best guess is that he lived in an alternate universe where we're a TV show to them and they're a video game to us."

"I was really hoping it was wrong because what they went through was most definitely not of the good. But if who you are is accurate that means that most of the stuff I remember from that show is also probably accurate, and life is going to be of the major suck for the next couple of years." Xander said glumly as his teacher stared at him like he was nuts.

"But…but!" She sputtered.

"And to answer your question I have an eidetic recollection of Desmond's life along with all of his ancestors who he'd accessed through the Animus. Including all of skills, knowledge, experience, and training that any of them had. I remember living all of their lives as if they were my own. So I have the memories from birth to death of Desmond Miles, Altaïr ibn-La'Ahad's, Ezio Auditore da Firenze, and Ratonhnhaké:ton. I lied about that on the off chance that Desmond's memories were accurate. We're gonna need the surprise factor."

Taking several seconds to compose her thoughts, the Romani then asked the most pertinent question in her mind, "Why?"

"The most time sensitive reason is because when Angelus returns he won't see me coming."

His reply shocked her senseless again. Feeling light headed the beautiful teacher put her head in her hands and leaned against some wall lockers for a moment before turning to fully face her student. "Tell me everything."

Opening the door to her classroom, Xander let her enter first as he began. "When Abstergo Industries kept Desmond a prisoner in between animus sessions he had to have something to do, so he watched TV. To try and keep him content, Lucy the undercover Assassin working there, was authorized to bring in copies of all the episodes for his favorite shows so that he could watch them whenever he wanted. Buffy the Vampire Slayer and its spin off Angel were the ones he watched the most but there was also the Dresden Files, Charmed, the Vampire Diaries and another show called Supernatural among others."

Catching an inquiring look from his teacher he commented, "Desmond had a thing for a genre called urban fantasy. And since he was kept from being able to do literally anything else, he pretty much memorized all the episodes for those shows."

"I guess, I've heard of Charmed but not the others." She said.

"Yeah, they won't air for another couple of years, if they even get made in this reality. Anyway, when I gained his memories I also gained his encyclopedic knowledge of those shows. He was there for a year with nothing else to watch or do so he ended up memorizing all of them. His memory of the first season of Buffy perfectly matched what I remember happening last year. So far this year seems to be the same, except for the swim team incident happening before Halloween instead of in the spring. And me dressing up as him, in the episode he watched the Xander character dressed in army fatigues and spent the night calling himself Private Harris." He paused and looked her in the eye as an obvious internal debate took place. With a look of resolve on his normally cheerful face he continued in a quiet, even voice. "But the important part for you is that Angel loses his soul on Buffy's 17th birthday and goes on a rampage. He kills you when he finds out you are working on a way to curse him with a soul again."

Staggering as the young man informed her of her death. Janna of the Kalderash clan of the Romani felt like she was going to throw up. "How did the curse break?"

"The curse had an escape clause as all curses do. And it was crafted in the 19th century so they thought they'd come up with the perfect way to prevent the clause from triggering. If the demon achieves a moment of perfect happiness the soul is lost and Angelus comes out to play. Well on her 17th birthday Buffy decided to get her cherry popped with a demon ridden corpse and voila. Moment of perfect happiness achieved. Nobody back in the day ever thought that a girl would willing fall in love with let alone have sex with a dead guy. I guess they'd never heard of necrophiliacs before."

"I think I'm gonna be sick." She said as she flopped into the chair at her desk.

He grabbed a seat in the front row as he continued. "Yeah, I know how you feel. I'm supposed to spend the next 5 years basically being the servant/Renfield of the group before getting my eye gouged out by a psychotic priest. Willow gets addicted to magic, goes insane and tries to end the world. Angel gets his soul back after what he did to you and about 40 random people here in town before getting to go off and be a Champion of the Powers that Be. He ends up working for an evil law firm in L.A. Buffy…well let's just say that she becomes arrogant and reckless. Giles never gets over you and pretty much just goes along with whatever Buffy wants. It's a whole lotta bad all the way around."

"So why are you telling me this?"

"Because thanks to that damn possession I know exactly what'll happen if I confide in any of them. I now have literally five of life times of experience in dealing with people and friendships. Looking at them objectively through the lens of my new experiences, I now know that neither Willow nor Buffy are very good friends. Buffy is a self-centered, narcissistic, and self-destructive little girl with powers that she claims to have never wanted but would never give up. She's also a 16 year old girl who has literally had a planet ton of crap land on her and is barely dealing. She's in desperate need of psychiatric counseling but good luck finding a counselor that could handle her issues and not just automatically assume she's insane. If I tell Buffy she'll just assume that what's happened to me is evil, both because I don't really have a great track record with magic and because she couldn't handle the competition. She'd just demand that Giles and you get rid of it just like with the Hyena possession last year, which granted needed to be gotten rid of since I couldn't control it. But as far as she's concerned I'm ONLY human and no mere human has any business getting involved in her fight. In her mind I am not allowed to be involved in the slayage except as backup. If she found out I've got skills to match hers…well she'd see me as a threat and it wouldn't end well. I can't talk with Giles because he'll tell Buffy or he'll just try to block or suppress the memories on his own out of guilt for what he and Ethan did 20 years ago. As for Willow…don't get me started on her."

"Why? What about Willow?"

"Well having known many childhood friends from several different time periods means that I now filter all of my Xander memories through the lens of those experiences as I said. And looking back on our lives together leads me to the conclusion that she was only friends with Jesse and me because we paid attention to her and let her be the brains of the bunch. She reminds me of some of the scientists at Abstergo and other Templars throughout history. She wants to know…everything and never stops to think about the consequences of her actions. Buffy gives her the self confidence to believe that because she is more intelligent than most, she knows better and doesn't have to take other people into account. And to complicate matters, she thinks she's in love with me."

"And I take it you don't feel like that for her."

"Uhm…I'm gonna go with no. Before Halloween I saw her as my sister, my best friend, my yellow crayon buddy." Seeing her enquiring look, he continued. "Long story. Anyway, I've never had nor will I ever have romantic feelings for her. But she has apparently been going around thinking we're going to get married since she was a little girl. According to the show, she ends up being gay. I don't know if that will still happen or not but what I do know is that if things had gone as they did in that timeline, we would have had a brief affair next year that would have wrecked my love life since we were both cheating on our respective others and when we were found out Willow blamed everything on me. Buffy, Giles, my girlfriend, hell even her boyfriend agreed with her that it was my fault and I took advantage of her." He said finished in a bitter voice.

"I see." Janna responded in a subdued tone, as she was still preoccupied with the thought of her death at the hands of Angel.

"But see that little story arc never made sense to Desmond. You don't just suddenly decide completely out of left field that the girl you've considered your sister for your entire life is the girl you want to be with. And even if you did, Desmond didn't think that the Xander character in the show was the type to cheat. He gave me enough credit to assume that if I were unhappy with my girlfriend, I'd discuss it with her or at least tell her that I was being tempted in another direction and break it off cleanly rather than sneak around behind everyone's backs."

"True, you don't strike me as the type to be a weasel like that." She agreed.

"Thanks, Desmond always assumed she was doing an unconscious love spell on that Xander, since that was the type of stuff that happened to her pretty regularly once she got serious with the mojo. Plus, none of the Scoobies deals well with change. The fact that I'm not their goofy comedic relief sidekick anymore will cause them to go ballistic."

Scratching his head after taking a minute to calm down from his rant, Xander continued. "All of this is neither here nor there. Bottom line, I've got the skills and experience to make a real difference here on the Hellmouth but I'll be sidelined if the others find out about it. I figure between the two of us we can work to change what was going to be."

"What do you have in mind?"

"Well for starters, you need to come clean to the others about who you are and why you're in Sunnydale. Easiest way to prevent the curse being broken is to explain to Buffy and Angel why they need to break up. Plus, in the original timeline, you were outted after the curse was broken and Buff used that as an excuse to shift all the blame onto you rather than think that all of those people died because of her actions. If you do it now, Giles and the others will be upset but it won't come back to bite you later AND it will explain why those two being together is a bad idea."

"And before you say anything, if I were to try and convince either of them to break up with the other they'd both ignore me and accuse me of being jealous since I had a crush on her last year."

"I see. And I take it from the past tense that you don't have a crush on her anymore and you aren't jealous?" She asked archly with a raised eyebrow?

"Ah, no. Honestly other than her looks, she does nothing for me. The fact that she used me for a stripper pole to make Angel jealous when she came back at the end of the summer effectively killed any attraction I had to her. Her actions that night showed me that as far as she was concerned I wasn't a person, just an object to be used to make her feel better. She never even apologized for it. Before being possessed I never would have made a big deal out of it, because of the whole lack of self esteem issue, but now I can look back and say that it was messed up and I have no real desire to remain friends with someone who treats me that way. I get enough of that from my parents, I don't need it from my friends. Unfortunately she is the Slayer and we need her for now. Once I've advanced some of my other plans and I've got a viable way to fight against the nightlife without her, I'll walk away never look back."

The young teacher stared at the oldest teenager she would ever meet, trying to comprehend the massive changes he'd undergone since yesterday afternoon, and ashamed that she'd never discovered how bad his home life was. She was feeling oddly humble that he would entrust her with his deepest secrets and she silently vowed that she would do all that she could to help him.

"Alright, I'll try to come clean to Rupert tonight and he can figure out how we're going to fill the others in. What else?"

"Well, there are some discrepancies in the timeline that I need to figure out. For instance, in the original timeline, as said I went as a soldier not an Assassin. Cordy got her costume from Party Town and wasn't transformed." He said, silently deciding not to mention Dawn's extra-dimensional origin to anyone before he discussed it with her. "So I want to talk with her and find out what, if any, changes she's undergone. I also need to get the process started for me to be emancipated so I can get out of my so called parent's house. If we can prevent Angelus from rising and Drusilla from getting back to full power we should be golden till next year. There aren't any major big bads to worry about other than those two."

"Well in that case I better get home and contact my people and see if I can get a copy of the soul curse spell, just in case we end up needing it."

"Sounds good, good luck with Giles tonight, and I'll see you on Monday." The young man said as he made his way out of the classroom.

AN: I'm rewriting this story because it was the first fan fic I'd ever written and I went a little overboard with it. Most of characters were a little too munchkin and it was too hard keeping track of all of them. I've kept it mostly the same just tweaked it so that not all of the characters are going to be uber powerful.