Hell breaks loose in Hallownest (Doom slayer reader x hollow knight)

Prologue

(Y/n)'s POV

I was currently fighting the Spider Mastermind. I hit it with a burst of rockets from the rocket launcher and it falls to the ground. Now's my chance. I walk up to it and shove the BFG down the thing's throat, letting off a shot and instantly killing it. It's done. I've saved the space station and all of Earth. We're safe.

I'm blinded by a familiar blue light and as my vision returns I'm back on the space station on Mars in a dark hallway and...I can't move? My arms are chained up and I can't move. I see a familiar tall robot walking towards me. Samuel Hayden.

"You've won - it's over. You stopped the invasion and closed the portal. But it's come at a price - Argent, VEGA. This entire operation. You see, I've watched your work - come to understand your motivation. You may think the only way is to kill them all - leave nothing behind - and you may be right. But we can't just shut it all down. Without Argent Energy it will be worse. I don't expect you to agree."

He then pulled the crucible from me with some kind of magnets on his hand.

"But with this we can continue our work. I'm not the villain in this story. I do what I do because there is no choice." The station A.I then speaks.

"Re-routing tether coordinates... Complete." Hayden starts speaking again.

"Our time is up. I can't kill you - but I can't have you standing in our way." He then activates the Crucible.

"Hayden, you bastard!", I shout. "You don't get it do you?! Argent Energy is the reason this all started in the first place! You seriously doing it again is a good idea?!"

"You do have a point, but remember it was all Olivia's fault. With her no longer in our way, we can use Argent Energy the way we want to. We can truly utilize it's full potential, and secure humanity's future. Until we see each other again...

(Y/n)". He then walks away. 

"HAYDEN!", I yell out but to no avail. The tether activates and I'm teleported away to God knows where.

...

I woke up with a massive headache on a cold, hard, rocky ground and slowly pushed myself up. Oh when I get my hands on that two-faced heap of scrap...

I studied my surroundings and saw that I'm in a rather dead looking place. Kind of like hell but more barren and depressing than angry. Still, you can never be too careful. I equipped my shotgun with the explosive shot attachment and advanced forward, looking out for any signs of danger.

Before long, I came across a barren looking town and saw an old wooden sign that said 'Welcome to Dirtmouth'. Weird name for a town but whatever. I kept walking forward into the town until I saw a weird looking creature I'd never seen before, but guessing from his features, he was rather old.

"Ah, hello there", he greeted. "Nice to see another traveler passing through, we don't get too many of those, even if you are rather frightening looking". I expected as much. Just the sight of my armor is enough to even make the most powerful beings in existence shit their pants, not to mention that I towered over him by a good 2 feet. He seemed no threat so I put away my shotgun. "What might your name be, traveler?" I tried my best to speak but my voice was slightly raspy after not speaking for a thousand years.

"Y/n. And you are?" 

"My name is Elderbug. Pleasure to meet you, Y/n." We then shook hands. 

"Say, you wouldn't happen to know what's inside that tent, do you?" I looked behind me and saw a scarlet colored tent that stood out from everything else. How did I not see that until now?

"No, I can't say I do", I replied. "Well do you think you can go see for me? I'd go there myself but I'm not one for adventure and it looks rather suspicious if you ask me. Judging by your looks I'm sure you're more than capable of handling yourself." 

"Sure thing. I'll be right back." I turned around and went into the tent taking out my shotgun again. My berserk power up was ready so I wasn't worried. It was dead silent inside. I walked down a long hallway into a large room that I didn't expect to see in what seemed like such a small tent. Judging from the seats on the opposite side of the room it looked like I was on a stage, but it was completely empty. Then out of nowhere another strange looking creature, even more so than Elderbug, teleported in front of me.

He had bright red eyes, white face with the top of his head being black, and a grey cloak that went all the way down to his ankles. He then spoke. "So, a new explorer appears before us. And who might you be?" 

"Y/n, but I'm also known as the Doom Slayer."

"Well Y/n, it's a pleasure to meet you. My name is Grimm. I'm the master of this troupe." He held out his hand, which I shook. It's then I noticed he was around the same height as me, around 6 foot 5, maybe a couple inches shorter than me. At least I didn't have to bend down to greet him like I do with most people. 

"So Y/n, where are you from? I always enjoy hearing about the far off places that new arrivals come from." I hesitated to answer.

"Well, its...Complicated." Grimm only chuckled. 

"Oh please, I once met someone who claims they were raised by unicorns. But I will admit he was quite... out there. It can't be that bad." Ok, now that was pretty weird, I had to admit. 

"If you're really confident that it's as complicated as you say then why don't we sit down over a cup of tea." He then led me throughout the tent for a good minute to another room with a table, 2 chairs, and a couple cups of tea already there and we both sat down both sat down. I took a silent breath in and began to tell him of my home, how it was destroyed, how I went on rampage for thousands of years in anger over the demons taking everything, the comrades, I was supposed to protect, the Argent Gods, my brothers in arms, and my son. I then told him of getting trapped for a thousand years after killing the Champion of Hell, up to awaking, finding the crucible, and being sent here by Hayden after he betrayed me and showing up here outside of the town. He seemed to be processing everything by the time I was done.

"Well..." he said after taking a sip of his tea. "It seems you weren't lying when you said it was complicated. How are you holding up after all of that?" 

"I guess I'm doing ok. I'm not nearly as bloodthirsty and rage filled as I once was. But unfortunately I don't seem to have a way home yet."

"I see", Grimm responded. He seemed to be deep in thought for a while. 

"Say, have you ever been into the arts before? You know, music, dance, things like that? I know it seems like a stupid question, considering what I know about you so far, but still." I thought back to the time before I lost everything and went blind with rage. 

"Well I was into guitar a whole lot when I was young. One of the best in my dimension." "Grimm's eyes widened in surprise. "Really now? Well in that case I have to ask...

Would you like to join the troupe?"