Rias POV

      After the fight with Battra, I wanted to see (Y/n) and apologize to him for succumbing to the monster's mind control, but he swam back into the ocean without so much as a word.

Issei: I knew it. He is just another mindless jerk taking you for granted.

Koneko: Like you did any better, Pervert.

     Issei instantly went red in embarrassment.

Akeno: I'm sure he had a reason to return to his training under the sea.

Rias: Well, I'm going to find out.

      I use my magic to detect (Y/n)'s location and open a portal to him, I walk through and see him actually sleeping, I march over to him and am about to kick him in his special area when I see he is breathing rather heavily.

Rias: *worried* (Y/n)!

     I kneel down to him and start using my magic to start healing him and restoring his energy. (Y/n) opens his eyes and slowly looks at me.

(Y/n): *weak* Rias.

      His eyes close again and he falls unconscious, I quickly use my magic to find anything wrong with him. Initially there was nothing, but as I checked a cut, I noticed his blood had a muddy tinge to it. I then use a spell to locate and remove any more of the mud in his system.

(Y/n): *sudden inhale of air* *coughs*

Rias: (Y/n)?!

(Y/n): *cough* Rias. *cough* *cough*

Rias: What happened?!

(Y/n): *heavy breathing* Smog..... Monster.

Risa: What? Nevermind, let's get you home.

      I pick up (Y/n) and carry him through a teleportation circle, Asia immediately got work on healing him and removing any more of that toxic mud. I wait patiently while looking for any reference to a "Smog Monster", but I can't find anything on it. Eventually, (Y/n) does regain consciousness and I ask him what happened.

(Y/n): After the Battra fight, I was going back to the undersea temple to recuperate and then come back to you, but something happened on the way down. I swam through a pollution spill and kept going until something grabbed me and tried to engulf me, I tried to bite and slash and that wasn't working, but when I tried to use my atomic breath I couldn't. I found it hard to breath so I made it to the temple, hoping the heat would halt it's attack. That's around the time you found me.

Rias: I'm glad you're alright but I can't any reference to a smog monster.

(Y/n): *after a moment* Godzilla says he's never heard of one either.

Rias: This is worrying. This is beyond my skill to figure out what this is. We'll need human science to help find out what this is.

(Y/n): I don't suppose you know a science genius do you?

Rias: Hmm, actually, I just might.

     I still had some of that toxic mud and placed it in a vial and teleported to a science lab in Tokyo and called upon an old colleague.

Rias: Hello, Dr. Serizawa.

Serizawa: Rias? My goodness so wonderful to see you, Milady.

Rias: It's been too long.

Serizawa: Can I offer you some tea?

Rias: I can't stay long, but I do need you're help with something.

Serizawa: Of course.

Rias: *pulls out vial* This mud made a friend of mine very sick, he was able to beat the illness but I need to know what made him sick in the first place.

Serizawa: *takes vial* Interesting. It looks like mud with small flecks of something. I'll have to put this under a microscope to be sure.

Rias: Let me know what you find.

Serizawa: Of course.

    I return to the clubhouse and check on (Y/n), who is training hard in a special training room made specifically for him, just without the radiation.

(Y/n): *notices me* Oh. Hello, Pres.

Rias: *giggles* You haven't called me that for a while.

(Y/n): Well, I figured you might still be upset with me over me not returning to you immediately. Plus, professionalism in the work space.

Rias: I suppose. I'm not as upset as I was before I found you. How's your recovery?

(Y/n): *smashes truck sized boulder with a tap* You tell me. *chuckles* Any luck with your contact?

Rias: He'll let us know when he finds something.

*ALARM*

(Y/n): Isn't that a citywide evacuation alarm?

Rias: What's going on?

     I use my magic to take a look outside.

Rias: *something flies across screen fast* What was that?

      I watched as a cloud of, something, drifts down to the streets, the people then start coughing and then dissolve into skeletons.

Rias: *horrified* Oh no.

(Y/n): *to himself* Smog Monster. *growls*

Rias: What?

(Y/n): That's the same, um, thing, that attacked me. *starts walking away*

Rias: Where are you going?

(Y/n): I can lead that thing away from the city while you and the others get people to the old nuclear bunkers.

Rias: Wait, please, let's think about this for a minute.

(Y/n): We don't have a minute. People are dying out there.

Rias: We don't know what that thing is or what it can do! I order you to remain here until we can come up with a plan.

(Y/n): I'm sorry, but my heart won't allow me to follow that command.

Rias: You are my pawn and you will obey your king!

      (Y/n) walks out and activates a teleportation circle and goes through it. I only gave that order because I didn't want him to get hurt, but it seems I can't stop him anymore.

(Y/n) POV

     The teleportation circle takes me to the deep part of the bay just outside the city.

Godzilla: I know that wasn't easy.

(Y/n): Let's just get this done. Rias and I will deal with our issues later.

     I transform into my 400 ft. Godzilla form and swim back to shore, I rise from beneath the waves and make it the rest of the way on foot. Once there, I finally get a look at the thing in the sky...

... I take in a great sniff and something is immediately clear to me.

(Y/n): *thoughts* You smell toxic! *ROAR*

      I start marching towards this monstrosity, which is saying something coming from me, I remember the mud got into my bloodstream because of the various cuts Battra inflicted, so as long as I don't have open wounds I should be okay. Still gotta watch out for that mud though.

(Y/n): Alright, try some Atomic Breath Mutha Fu- *fires*

https://www.youtube.com/watch?v=ISqg6CRPsOI

(Y/n): *mind* Alright, direct hit!

      The smoke clears and-

(Y/n): And it did absolutely nothing to it, awesome.

     The sludge, monster, thing whatever it is flies towards me and it releases a spray of mud that covers not only me but the ground around me, killing even more people. Okay, now I'm mad, I charge up another Atomic Breath and hit the monster dead on, however it does nothing to hurt it, but it did make the creature turn around and charge at me. I widen my stance and ready for his attack, at the last second I duck under the monster and grab it's tail end in my mouth and spin it around and around then finally throw it outside the city limits. I was about to go after the monster when I get hit in the back-

(Y/n): Whoa! What was that?!

      I turn around and look to see some military tanks and helicopters.

(Y/n): *angered annoyance* Seriously, I'm trying to help. Ugh, I don't have time for this.

      I turn around but can't react in time to dodge the Smog Monster's grab, the monster slams into me causing me to stumble backwards and eventually fall on my back as the monster starts to envelope me with it's body.

Rias POV

Issei: What the hell is the military doing? (Y/n) is only trying to help!

Akeno: We know that, but everybody else just sees two giant monsters.

Xenovia: *as (Y/n) is lifted off the ground* We have to do something! (Y/n) isn't making any headway on his own!

Gasper: I vote we just hide! *hides in his box*

Kiba: But what can we do? If (Y/n) can't damage it, what good are we against that thing?

Rias: I need to check on something. Don't do anything until I get back.

      I take a few steps and use a magic circle to teleport to Dr. Serizawa's workplace, he looks up at me as I briskly walk towards him.

Serizawa: Rias, what are you-

Rias: I'm sorry to rush this, *grabs tv remote* but have you had a chance to look at that sample I gave you?

Serizawa: I'm looking at it now, why?

      I turn the news on and we both see Godzilla struggling to get out of the Smog Monster's grip, (Y/n) tried a Nuclear Pulse but the radiation wasn't affecting it.

(Y/n): *ROARS*

Serizawa: *disbelief* Is this real?

Rias: ....Yes. The mud monster is hurting people and we need to figure out how to stop it.

Serizawa: Uh, right. This sample you gave me has trace elements of irradiated mud and flecks of random trash like bottles and other plastic.

Rias: So, it's a trash monster?

Serizawa: In away yes. I did find something interesting though, when I put a few droplets of water on the mud it started expanding.

Rias: So, dehydration is it's weakness. If we find a way to rob this monster of water we could defeat it.

Serizawa: *thinks* If I remember, there is a huge super heated electrode plant outside Tokyo. If we could somehow lure that monster there the electrode will dehydrate the monster.

Rias: Make your way there, we'll get the monster to you. *starts walking away*

Serizawa: How?

Rias: I, don't know. *teleports away*

     I return and see my clubhouse is empty, then I hear explosions outside.

Rias: Oh no.

     I run outside and see Issei and Xenovia attacking the monster but their attacks are having no effect.

Akeno: Rias!

      Akeno flies down and sees I am not very happy.

Rias: I thought I said not to do anything until I got back.

Koneko: Blame the pervert, he wouldn't stop even if we told him not to.

Asia: That thing started carrying (Y/n) away towards a suspected pollution spill, we had to do something.

Rias: *sighs* I'll deal with all of your punisments later, for now though, I have figured out this things weakness. Let's go.

(Y/n) POV

       I have been struggling to get free of this Hedorah's grip, everytime I try to pry myself free I get pulled in further, eventually, I free my hands and start pulling and slashing to pull Hedorah off me. Until, suddenly, Hedorah drops me and I land in the water, my first thought was, I finally have the advantage, until the same black sludge that hurt me in our first encounter started surrounding me.

(Y/n): What now?

Godzilla: Mind your gills!

      As soon as Godzilla says this my gills start getting stuffed and gluey, then I find myself unable to breath and as the sludge continues to surround me I can't find the surface of the water.

Rias POV

Rosweisse: Is it just me or is that thing growing?

Rias: This monster feeds on pollution and is unstoppable while it's hydrated.

Issei: So, how do we get this thing to follow us? It's where it's most comfortable and close to taking down Earth's greatest defender.

Rias: We hurt it.

Kiba: How?

Rias: *casts spell* HYAH!

     My spell seemed to get the monster's attention, Akeno, Rosweisse and Issei join in annoying the monster enough to get it to follow us, while also letting go of (Y/n)'s now unconscious body.

Rias: Lead it to the Electode outside Tokyo! Asia, with me.

Akeno: Hit and Run everyone! Move it!

     Asia follows me and we skirt behind the monster and get to (Y/n), who has transformed back into his devil form to lessen the strain on his lungs. The monster transforms into a new form and goes after the group as Asia and I land next to (Y/n).

Rias: We need to get the sludge out of his lungs.

Asia: Right.

      I takes Asia and I several minutes but finally the mud is out of (Y/n)'s system, but he still isn't waking up.

Rias: Come on, (Y/n). (Y/n), wake up! Come on!

      I lean down and try breath into his mouth to get his lungs moving again, finally-

(Y/n): *inhales sharply* *coughs* *groans* Okay, I need to stop doing that. Ow.

Rias: Take it easy, just breath for a minute.

(Y/n): *breaths deeply* Where's... Hedorah?

Rias: We've figured out the monster's weakness, dehydration.

(Y/n): That.... actually makes sense why I couldn't damage it or overpower it in the water.

Rias: Akeno and the others are leading this, Hedorah, to a large electrode unit just outside Tokyo. When it turns on the power super heats and will dehydrate Hedorah making it vulnerable.

(Y/n): Let's not keep the others waiting.

     (Y/n) recovers and the three of us start flying towards Tokyo. Eventually, we get ahead of the monster, except (Y/n) rejoins the fight and helps draw Hedorah. Asia nad I fly towards the electrode and land near the control station and see Dr. Serizawa waiting.

Rias: Dr!

Serizawa: Rias-

Rias: Get ready, the monster's on it's way!

Serizawa: How did-

Rias: Just get ready!

     Dr. Serizawa just shuts up and prepares the electrode.

Serizawa: There, all I need to do is flip this switch.

Rias: Fire on my signal.

(Y/n) POV

     Now that Hedorah is confines to the ground I can do more to help and drive it towards the electrode. As we come over a small hill I can see the electrode, so I charge in and tackle Hedorah sending us down the hill and apparently into the test sight, because I heard Rias' voice in my head.

Rias: (Y/n), get out of there, you're gonna get hit!

      I recover a lot slower than Hedorah, but when I did I could see Hedorah trying to get away, I reacted by launching an Atomic Breath at Hedorah, which while it didn't hurt it, the force does make it stumble, allowing me to grab Hedorah and pin it.

Rias: *telepathy* Get out!

     Hedorah tries to get up by grappling me with it's muddy body, I know I'm not getting out of this, I glance at Rias, who has a worried expression, and I simply nod at her.

Rias POV

Serizawa: Rias, it's now or never.

Rias: *sighs* Do it.

      Dr. Serizawa ramps up the power on the electrode and the machine shoots out powerful electrical shocks, which hurts both monsters but is uaving more of an effect on Hedorah than (Y/n), thankfully. Suddenly, the machine stops working.

Issei: What happened?

Serizawa: Oh no, the electrode is malfunctioning.

Rias: Meaning?

Serizawa: The electrode won't work we need to find another way to super heat those plates.

That gives me an idea.

(Y/n) POV

      I felt the electrical surge and endured the pain until it stopped and looked to see Hedorah start letting go of me to try and get away. I then hear Rias again...

Rias: *telepathy spell* (Y/n)! Your Atomic Breath!

(Y/n): Doesn't effect this thing!

Rias: Not at Hedorah! Focus it on the electrode plates and reactivate the machine!

     I quickly grab Hedorah and put it in a hold, I then charge up an Atomic Breath...

https://www.youtube.com/watch?v=ISqg6CRPsOI

....and aim at the massive plates, when my breath does hit them, the machine reactivates and I feel the electrical surge but a lot more powerful. I tough it out and keep holding Hedorah until the pain stops, I release the Smog Monster and stumble a little bit. When I regain my footing, I see Hedorah has slumped to the ground, I lean down and start tearing it to pieces, I then fire another Atomic Breath and this time the monster's corpse turns to ash, I then release a victorious roar....

https://www.youtube.com/watch?v=JkUQ6s4mrWw

I then look down at my friends and then turn around and return to the sea, via Tokyo bay. Even though we won, I disobeyed my master and, by devil law, will be considered a rouge devil, and I felt bad about putting Rias in that position. So, to spare everyone pain, I went back to the ocean and first went to the undersea temple to recharge, then start patrolling the pacific ocean and keeping a vigil for not only monsters but also keeping an eye on my friends.

Rias POV

Rias: Brother, you can't be serious?! (Y/n) only disobeyed me because he did what he felt was right, you have to be willing to look past this!

SirZechs: I'm sorry, dear sister, but (Y/n) broke the rules set in place by Satan at the beginning of time. If he doesn't harm any devils or humans for the time being I will be willing to let him back into your peerage. Until then, he is from this point forward a rogue devil. That is my final word on the matter.

     My brother leaves and (Y/n) left and I couldn't even say goodbye to him...

Akeno: Rias?

     I couldn't hold back anymore and pushed past everyone and went to my room and locked it, I just burst into tears to think I might not see (Y/n), the person I cherish the most, for hundreds if not thousands of years. After several minutes, my crying slows and I remind myself that he still cares deeply for me as do I.

Rias: If you ever need me (Y/n), I will come, whatever the reason. I love you.

Serizawa POV

     I can't believe it after nearly 50 years, he has finally re-emerged, I grab my dad's watch out of my pocket and remember the day it stopped working, the day the atomic bombs dropped.

Serizawa: Welcome back, old friend.

(A/N): Man, what a bummer, huh? Hopefully, things will work out in the future. Hey, sorry for the tardiness, I was having serious writer's block with these monster fights, I hope it was worth the wait. Thanks for hanging in there and I'll start paying attention more to this story as well as the others before doing something new. As always, if you liked this chapter, leave a vote. And if you're new and want to see more of my content go to my page and consider following me so you never any new updates from me. Love you all, and I'll see you next time. PEACE OUT!!!