You stare at Mettaton while your soul is yellow and pointing at him

Y/n: Guess you are the one in charge then, huh? Who made everything harder?

Mtt: YES, I WAS THE ONE WHO RE-ARRANGED THE CORE! I WAS THE ONE THAT HIRED EVERYONE TO KILL YOU! THAT, HOWEVER, WAS A SHORT-SIGHTED PLAN. YOU KNOW WHAT WOULD BE A HUNDRED TIMES BETTER?

Y/n: What?

Mtt: KILLING YOU MYSELF!!

Chara: Great, of course

You start shooting at him and the bullets just bounce off

Mtt: That pea shoot is worthless against me, darling, don't you understand acting?

Y/n: It was worth a shot

Somewhere in the underground, a skeleton is smiling to himself and the other is almost throwing a tantrum

Mtt: Listen, darling. I've seen you fight. You are weak

Chara: Oh no...

Mtt: If you continue forward, Asgore will take your soul. And with your soul, Asgore will destroy humanity.

A lot of squares fall in your direction but you just bitch-slapped them all without even caring

Y/n: Weak, huh?

Chara: Y/n, Calm down... We're trying to make a pacifist run in here...

Mtt: But if I get your soul, I can stop Asgore's plan! I can save humanity from destruction!

He proceeds to try to punch you but you weren't even fazed by his attacks

Y/n: You're just so full of yourself, aren't you?

Chara: CALM DOWN BOY! Don't worry about it

Mtt: Then, using your soul, I'll cross through the barrier and become the star I've always dreamed of being! Hundreds, thousands... NO! MILLIONS OF HUMANS WILL WATCH ME!

He kept attacking you, but his attacks didn't even make a scratch on your clothes

Mtt: Glitz! Glamour! I'll finally have it all! So what if a few people have to die? That's show business, baby

Y/n: SO WHAT? SO WHATEVER IF I KILL EVERY SINGLE MONSTER IN THE UNDERGROUND AND LEAVE YOU BY YOURSELF HUH? SO WHAT IF I KILL ALL OF THEM! IT'S JUST SOME LIVES THAT DON'T MATTER! I DON'T CARE IF I HAVE TO CLEAN THE UNDERGROUND JUST TO GET OUT OF THIS CURSED PLACE!

Chara: Y/n CHILL THE FUCK OUT!

The first time as a blessing, your phone rings

Chara: FINALLY!!

Alphys: U..uh... I can't see what's going on in there, but D-d-don't give up, okay? Th...there's o-one l-l-last way to beat Mettaton... It's... Um... It's... THIS IS A WORK IN PROGRESS SO DON'T JUDGE TOO HARD... But, you know how Mettaton always faces f-f-forward? There's because there's a switch on his backside. S-s-so if y-y-you c-c-can turn him around... Um... And, umm... Press th-th-the switch... He'll be... Um.. He'll be... Vulnerable. Well, g-g-gotta go!

She hangs up and you are still angry at this robot, but you try to keep you cool

Y/n: So shit-head, is that a mirror behind you?

Mtt: OH??? A MIRROR???

Chara: I can't believe this...

Y/n: I guess it is, look

Mtt: Right, I have to look perfect for our grand finale!

He turns around and you start inching towards him

Mtt: Hmm... I don't see it... Where is it?

You flip his switch as hard as you can, probably or almost breaking it

Mtt: Did you. Just flip. My switch?

Mettaton looks like losing his cool when suddenly you hear a sexy voice in the middle of the smoke

Mtt: Ohhhh yesssss

Chara: That's... I don't even want to talk about it

Y/n: All that smoke... I can't see shit...

Mtt: Ohhhh my. If you flipped my switch, that can only mean one thing.

Chara: Time to GTFOH?

Mtt: You're desperate for the premiere of my new body.

Y/n: How conceited can you get?

Mtt: How rude...

Chara: Really?

Mtt: Lucky for you, I've been aching to show this off for a long time. So... As thanks, I'll give you a handsome reward.

Y/n: What is it?

Mtt: I'll make your last living moments... ABSOLUTELY beautiful!

Mettaton EX makes his premiere!

Chara: This guy's very weird...

You notice the cameras and the ratings, so you pose dramatcally. The audience nods at you

Chara: What are you...?

Mtt: Lights! Camera! Action!

He starts dancing showing off his legs almost hitting you

Y/n: Nice moves, A-hole

You start dancing with him

Mtt: Drama! Romance! Bloodshed!

He starts throwing bombs at you and little mtts that launch some hearts at you hurting you slightly

Chara: This is getting out of control...

You pose dramatically, but the audience just nods

Y/n: It's showtime Mtt, let's end This!

Mtt: Smile for the camera!

He said while some of his robots fell from the ceiling hitting you with hearts

Mtt: Oooh, It's time for a pop quiz! I hope you borough a keyboard

Y/n: What?

Mtt: This one's an easy question!

What do you most like about Mettaton?

Y/n: Welp... Your legs are amazing...?

Mtt: That's right! "Legs" was the right answer!

You smile, turn, and scoff at the audience. They're rooting for your destruction this turn

Mtt: Your essay really showed everyone your heart. Why don't I show mine?

His soul came out of his body launching electric shocks towards you, so you used your own soul to shoot him back making he smoke a bit

Y/n: Come on dude, Do your best, you WON'T hit me!

Mtt: Ooooh, I'm just warming up

Some of his robots fell and you noticed that if you shot them they would break

Chara: Oh wow

You look at Mtt and pose like a JoJo Character. The audience nods at you smiling

Mtt: But how are you on the dance floor!?

A disco ball came from above shining blue and white lights at you, so you started moving avoiding the white ones and you sit still when the blue ones came towards you. Seeing this, you took the opportunity to hit Mettaton in the torso making the ratings increase

Mtt: Can you keep up the pace!?

The same light came down on you even faster, you danced fastly and at the end, posed dramatically

Y/n: Let's do it!

Mtt: Lights! Cameras! Bombs!

Chara: Bombs?

Some bombs fell from the ceiling and you shot them, making them explode, but you took cover rapidly and you just got a scratch in your arm

Y/n: C'mon! You ain't even trying!

Mtt: Things are blowing up!

The same bombs came down faster and faster, but you were able to shoot and dodge them all, seeing your victory, you pose absurdly dramatically

Chara: you're being just like him now

Mtt: Time for our union-regulated break!

You sat on the floor and rested for a minute, then filled with determination, you jumped out of the ground and posed dramatically again

Chara: Really?

Mtt: We've grown so distant, darling... How about another heart-to-heart?

His soul came out of his body again, but this time protected, so you started shooting breaking his protection and hitting his soul while he tried to shock you but your attack was stronger, so in your last shot, his arms fell to the ground

Y/n: Let's go buddy! Hit me if you dare! But try to get your arms back

Mtt: A... Arms? Wh... Who needs arms with legs like these? I'm still going to win!

More bombs and boxes fell from the ceiling and you dodged them all, but suddenly everything started reversing and you almost couldn't dodge that

Y/n: That was close...

Mtt: Come on...!

The same thing happened, but faster, you couldn't dodge in time, so a box hit your face making your nose bleed, but despite being hut, you still posed dramatically. The audience applauds.

Chara: You okay?

Mtt: The show... Must go on!

A lot of boxes fell from the ceiling, alongside with bombs, but you bitchslapped them all... Almost all of them... But at the end, you posed dramatically again

Mtt: Dr...drama! A...action!

The boxes and bombs fell again, but almost in the same place, so you just looked unamused dodging them

Mtt: L... Lights... C... Camera... Enough of this! Do you really want humanity to perish!?... Or do you just believe in yourself that much?

You look at him smiling while bombs fell and you destroyed them while taking cover

Y/n: I believe in me so much, that you can't even hit me!

Mtt: Haha, how inspiring! Well, darling, it's either me or you! But I think we both already know who's going to win. Witness the true power of humanity's star!

His soul was out of his body again, surrounded by two bombs, so you started shooting and noticed various legs coming towards you so you jumped over them shooting Mtt's soul so hard that his legs fell from his body too, but at the end of this act, you still posed dramatically

Y/n: C'mon pal, don't give up!

Mtt:...Then... Are YOU the star? Can you really protect humanity!?

His soul came out again, shooting directly at you, and you both started shooting at each other hurting each other. But, despite being very hurt, you posed dramatically, and the audience goes wild!

Mtt: OOH, LOOK AT THESE RATINGS!!! THIS IS THE MOST VIEWERS I'VE EVER HAD!!! WE'VE REACHED THE VIEWER CALL-IN MILESTONE! ONE LUCKY VIEWER WILL HAVE THE CHANCE TO TALK TO ME... BEFORE I LEAVE THE UNDERGROUND FOREVER!! LET'S SEE WHO CALLS IN FIRST!

His phone starts to ring and he answers it

Mtt: HI, YOU'RE ON TV! WHAT DO YOU HAVE TO SAY IN THIS, OUR LAST SHOW???

Blook:..... Oh......... Hi... Mettaton... I really liked watching your show... My life is pretty boring... But... Seeing you on screen... Brought excitement to my life... Vicariously... I can't tell, But... I guess this is the last episode...? I'll miss you... Mettaton....... Oh... I didn't mean to talk so long... Oh.........

Mtt: NO, WAIT! WAIT, BL... H... THEY ALREADY HUNG UP... I'LL TAKE ANOTHER CALLER!!!

???: Mettaton, your show made us so happy!

???: Mettaton, I don't know what I'll watch without you.

???: Mettaton, there's a Mettaton-shaped hole in my Mettaton-shaped heart.

Y/n: Looks like you're important to them

Mtt: AH... I... I SEE... EVERYONE... THANK YOU SO MUCH... DARLING....

Y/n: Yes?

Mtt: PERHAPS... IT MIGHT BE BETTER IF I STAY HERE FOR A WHILE. HUMANS ALREADY HAVE STARS AND IDOLS, BUT MONSTERS... THEY ONLY HAVE ME. IF I LEFT, THE UNDERGROUND WOULD LOSE ITS SPARK. I'D LEAVE AN ACHING VOID THAT COULD NEVER BE FILLED. SO... I THINK I'LL HAVE TO DELAY MY BIG DEBUT. BESIDES... YOU'VE PROVEN TO BE VERY STRONG. PERHAPS... EVEN STRONG ENOUGH TO GET PAST ASGORE. I'M SURE YOU'LL BE ABLE TO PROTECT HUMANITY. HA, HA... IT'S ALL FOR THE BEST, ANYWAY. THE TRUTH IS, THIS FORM'S ENERGY CONSUMPTION IS... INEFFICIENT. IN A FEW MOMENTS, I'LL RUN OUT OF BATTERY POWER, AND... WELL. I'll BE ALRIGHT. KNOCK 'EM DEAD, DARLING. AND EVERYONE... THANK YOU. YOU'VE BEEN A GREAT AUDIENCE!

A strong light blinded you for a moment, and you hear the door open, while looking to an uncharged Mettaton

Alphys: I... I managed to open the lock! Are you two...

She comes closer and sees Mettaton not moving

Alphys: Oh my God!

She rushes to him and starts moving and shaking him

Alphys: Mettaton! Mettaton, are you...

She looks to the side very relieved

Alphys:... Thank GOD, it's just the batteries. Mettaton, if you were gone, I would have... I would have... I mean, h-hey, it's no problem, you know? He's just a robot, if you mess it up, I could always j-just build another... Why don't you go ahead?

Y/n: Are you okay?

Alphys: I... I just need a moment.

You sighed and walked out of the room looking down to the ground

Chara: Are you okay?

Y/n: Yeah... We're almost reaching his castle now...

Chara: What are you gonna do?

Y/n: I have to free all of them... But I just don't know how...

Alphys approaches you quietly

Alphys: S... Sorry about that! L-let's k-keep going!

You both kept walking while Chara was looking at you worried

Alphys: S-so you're about to meet Asgore, h-huh?

Y/n: Yeah...

Alphys: You must be... Y-you must be... Pr... Pretty excited about all that, huh?

You just kept walking without talking

Alphys: You'll f-f-finally... You'll finally get to go home!

You kept walking and opened the elevator door at the end of the room

Alphys: W... Wait!

You look at her intrigued

Alphys: I mean, um... I...

Y/n: Yes?

Alphys: I was going to.......um... Say goodbye, and......

Y/n: And?

Alphys: I can't take this anymore...

She turns her back to you

Alphys: I... I lied to you. A human soul isn't enough to cross the barrier alone... It takes at least a human soul... And a monster soul...

Y/n: In other words...

She turns to you almost crying

Alphys: If you want to go home... You'll have to take his soul... You'll have to kill Asgore

Y/n: Yeah...

She starts walking away from you

Alphys: I'm sorry.

She then runs away from you

Chara: Oh no...

================================

A/n: Yeah... Oh no...