Everyone was shocked at what they saw. The show the slayer displayed by quickly defeating the boss and sawing that minion in half. They couldn't believe it, killing the first boss and not even getting a scratch. He never gave the thing a chance because he would never stay still, not letting the boss lay even a finger on him. Then once he finally killed the boss, he just walked away like he just finished some chore as some American heavy metal of some sorts played for practically nowhere. The music only adding to the menacing aurora radiating off him. Everyone backed up away from him as he walked past him, trying not to get in his way and end up the same way as the boss. Everyone watched as the slayer casually walked past them and out of the boss room.

Asuna pov:

She was stunned at the performance of the slayer. Seeing weapons that shouldn't be in here or even be able to be wielded by one person. First she saw him wield a giant crossbow, then he switched to a shotgun. Then the mercilessness he presented when he cut that minion in half with a chainsaw! In her opinion that was unnecessary and would have given her nightmares if this game was realistic. Then the fact he walked out without a care in the world and not claiming his loot confused her. Wouldn't anyone want to collect their loot after a boss fight? So many questions were running through her head, the most common was 'who is he?'. Asuna stood there staring at the slayer walk away into the distance as the music played, definitely something American, they like heavy metal.

Kirito pov:

As he stared at the slayer, he got the notification that he got the boss loot since the slayer didn't claim in. He paid no mind to it as he was still contemplating what happened before his eyes, then he remembered Diavel as he ran too him. He kneeled down next to him trying to get out a healing potion but he declined. Then he shattered like glass as he died, soon dying in the real world. He teared up as he witnessed someone die right in front of him.

Kirito pov:

Months have passed since the floor one boss. Players were leveling up, fighting bosses, and clearing as many floors as possible as fast as they could. Kirito had joined a small guild named the moonlit black cats. He fought monsters with them and did quests to try and level up as fast as possible. He never told them his real level because he was scared they would hate him, call him a cheater or something. He's also been friends with Asuna and Klein. Right now he was making his way up to the next floor to try and hunt stronger enemies to gain more XP and better loot. They were making their way down a hall and saw a room with a chest in the middle. They all saw it and ran towards it, but Kirito followed to try and stop them. He and his friends entered the room but he was too late to stop them. The door behind them closed, they tried to get out using teleport crystals but it didn't work. Suddenly they were surrounded by a bunch of enemies, try as they might, kirito's party was no match against them as they were slaughtered like animals. The last person he saw was Sachi, whispering something to him before she shattered, dying. Kirito was devastated, most of friends died, powerless to save them. All the monsters turned towards him, about to make him suffer the same fate. Until a loud bang sounded behind kirito. He looked back but saw nothing but the sealed exit. It sounded again as a big crack was made on the door. He and the mobs stared at the door in surprise and confusion. Then it broke open...revealing the unchained predator, the scourge of hell, hell walker, or better known as the doom slayer. Kirito was Aw struck, someone actually breaking through the barrier with ease. Then the fact the NPCs backing away from him also confused the black swordsman. Then he saw the single eye glow red in rage from the slayer, further increasing the intimidation.

Slayer pov:

He was walking around, killing as many of these abominations as possible, but they kept coming back after a while.

/it is futile to try to eradicate them, they will always "respawn" after a set time. I am sorry but it is impossible to permanently kill them to give the players safe passage/ Vega stated.

The slayer growled in annoyance as these things kept coming back. He hated the fact that he can't cleanse the place of monsters in this game. Back in hell the demons wouldn't come back to a place unless a demon made another gore nest to hell. He had Vega keep track on both Asuna and Kirito. They were the first two people whom the slayer actually 'talked' to when he first came here. The slayer tried his best to protect the players from dying but there were too many of them to save as thousands died.

/slayer, kirito is in a some sort of distress, possibly in need of help, setting waypoint now/ Vega suddenly said.

The slayer instantly took into action, sprinting to where Vega set the waypoint. He ran full speed, plowing through any enemy that got in his way. He wasn't going to let someone he knew die...not again anyways. He soon got to a sealed entrance of some sorts.

/scans indicate that Kirito is trapped in there along with a group of monsters/ Vega informed

The slayer then punched the entrance, making a crack. He did this two more times before it broke into rubble. He stared at the monsters who took a step back and saw kirito stare at him in Aw. His eye glowed red with rage as Vega informed him that kirito's friends were killed. He responded by jumping at the closest creature and grabbing it by its head and slamming it on the wall, crushing it into red shards. He then sliced the next with his doom blade and set more on fire with his shoulder cannon. He then got out his ballista and shot at one, getting a triple kill as it went right through leaving a fist sized glowing part in it before they shattered. One with a pickax tried to kill him but he grabbed the handle and ripped it out of its grasp before slamming it down on it. He slaughtered the rest with ease, the whole battle lasting 30 seconds. He then grabbed the shocked swordsman by the collar of his shirt and carried him out of the trap room. He set him down gently before walking away. He would make the creator pay for his crimes, and make his suffering slow.

Kirito pov:

As he watched the marine walk away, only now did he see what was on his helmet... the symbol, the same one that darkened the sky that day. 'Could it be? Is he the one the voice was talking about?! It can't be, he's a player, isn't he...' he thought. Then he remembered what happened in the trapped room, his friends all dying right before him. If only he stopped them sooner then they wouldn't have died. The vision of Sachi dying, saying her last muffled words repeating in his head. It would haunt him forever through his life, if of course he ever makes it out of here alive...

Slayer pov:

He walked away, slaying more and more monsters on his way. He was going to beat this game by getting to the hundredth floor, not before making the creator suffer. He knew he was in this game, watching and playing god, maybe even hiding as a player. He was going to hunt this man down and kill him. But he was proud of both Asuna and Kirito. And it enraged him when he saw Kirito devastated that his close friends were slaughtered like pigs. He balled his hands in rage at what Vega showed him of what happened before he got there.

/I have successfully downloaded the the fortress of doom into this game, you will now be able to travel there any time you like/ Vega announced.

Thank god, something good he heard these past few months. He missed the fortress of doom because it had most of the stuff he did carry with him. Opening a portal to it and walking through, entering into the main deck of it. He looked around and saw a music player and some of his favorite songs next to it. He decided he'd take a break and listen to some music while he was here, having Vega display the locations of Asuna and Kirito along with Video feed of them. For some reason, the slayer felt connected to them, like how he felt with his trusty AI that has been with him during his crusade. Vega has been with him for who knows how long, always helping whenever needed and giving him valuable info. One time, when he had to blow a hole into mars, Vega knew exactly what he needed and gave him the idea of using the BFG 10,00 to get to the ancient city within it. And it made him happy knowing demons could no longer invade and destroy planets, now imprisoned in hell.

Heathcliff pov:

He was annoyed, annoyed that some green and brown armored man by the name of the 'doom slayer' was killing boss after boss with ease. And now, some other floating building just spawned out of nowhere in his game. He tried to delete it but it just wouldn't work, some program called 'Vega' stopping him. Everything just made him confused and angry. Then he got an idea, maybe he could recruit him into his guild and use him as a puppet of some sorts. But that would be if he could even get ahold of the man in the first place. But for now, it's going to have to wait as he is busy doing work of his own.

Asuna pov:

She had joined the knights of the blood oath and was making her way to the floor boss along with others from her's and other guilds in the front line. Once they got there, they were met with the "congratulations, you defeated the floor boss" notification, shocking everyone present. 'Impossible!' She thought, then something came to her mind, the 'menace in green' as everyone called him, or as some know by his real name, the doom slayer. It had to be him who killed the floor boss, it's the only explanation. Then that's when they saw it, a stone pillar with the same symbol from the first day of being in this game, only green. Then it spoke...

" in the first age, in the first battle, when the shadows first lengthened, one stood, burned by the embers of Armageddon, his soul blistered by the fires of hell and tainted beyond ascension. He chose the path of perpetual torment. In his ravenous hatred he found no peace; and with boiling blood he scoured the umbral plains seeking vengeance against the dark lords who wronged him. He wore the crown of the knight sentinels. And those that tasted the bite of his sword named him...the doom slayer"

Everyone had chills run down their spines from the demonic voice and what it said. This only made Asuna more frightened because she had met the doom slayer. Now she was thinking less and less of the doom slayer being a player. And more of him being something else, she didn't even think he was an NPC with how he acted. More and more thoughts and questions ran through her mind as she stood there.

"Ma'am, are you alright?" Asked one of her fellow guild members.

"Huh? Oh yes, I'm...I'm fine..." she replied.

The guild member looked at her, knowing she wasn't but knew better than to push it as she was his higher up. She recorded the majority of it and was going to report back to Heathcliff of her findings.

Few hours later:

Asuna was on her way to inform her findings to the guild master when she noticed something floating outside of the floating castle she was in. She looked and her eyes widened along with other people who were around her. What they saw was another floating object, looking like a broken piece of a fortress of sorts. She knew it wasn't there before and wasn't sure what was going on anymore. She stared a bit more in aw before remembering what she was doing. She continued her walk, only taking peaks from over shoulder once In a while. Once she got to the guild place, she went up to the guild master office and knocked. Getting a "come in" from Heathcliff she walked in. She told everything she knew about her findings and showed the video of the stone thing speaking and the picture of the floating fortress. He seemed intrigued with the audio recording but not the fortress, saying he saw it on a trip to town. She was then dismissed and she left.

Another few months:

Asuna was walking to town until she came upon a tree, a sleeping Kirito under it. She looked and stomped up to him and kicking him lightly. He woke up and looked at her.

"Oh hi Asuna" he said sleepily.

"What are you doing, lazily sleeping under a tree, you should be out helping in the frontlines!" She yelled.

After a bit of convincing, Kirito finally got her to take a nap as he sat on the small stone wall outlining the path. He sat there till sunset before he looked back and Asuna as she woke up. She looked around with messy hair and some drool on the corner of her mouth. Then she realized the sun set and had a look of surprise and a quick "eeh?!". She got mad at Kirito for not waking her up sooner. She soon left and went about her day.

Author:

And that's it for this chapter! I hope you enjoyed it, and I do apologize for any timeline issues and inaccurate lore stuff. And SAO and Doom belong to their respective owns as I do not own them. I'm planning on having the slayer follow Kirito and Asuna on their little adventure from season one to season 4. I'll post another chapter ASAP, hope you come again for more and leave a like. Thank you and have a wonderful time!