My Upgrades Are Invincible

Even as my kick blasted Muzan several meters away from the house I had to franticly dodge by blasting myself into the ground as his arms morphed into a bladed whips and with a loud crack, they swung at me but with my throwing myself to ground they crashed into the front room of the house demolishing it but also sealing the Kamado family within making it so I didnt have to worry about them running around.

As his arms snapped back into normal shape, I saw Muzan puff up and his dress shirt audibly ripping as his chest and expanded and then he roared and like the Goliath back in the Danmachi I was buffeted by a sonic explosion but it a much smaller radius than the Goliaths, so I was able to hunker down and withstand the demons roar until he ran out of breath.

'I need to keep him on the back foot as his biological manipulation is practically endless and I don't have the stamina to fight him until the sun comes up like they did in cannon by throwing all there lives away.' I thought as I stood up and with a flash my huge katana flashed into my hands making Muzan visibly wince at the supernatural act.

"Muzan Kibutsuji, I must say I am honored to meet you today." I said cheerily which threw Muzan off and I could see him hold off whatever attack he was going to launch at me.

"Ohhh You know of me and yet you are not a demon slayer of this land and I have spent so much effort in keeping my demons confined to Japan, so are you a native?" Muzan asked me curiously obviously wondering about how an Englishman was able to kick him through a tree without using a breathing style.

"Well, you see I am a son of the goddess Hestia and really after hearing about you and the little circus of freaks you call your group, I decided to hunt all you little bastards down as your cruelty and perversions are endless." Let alone Muzan but Doma especially was a freak of the highest order, and I will only have good dreams and endless good karma from wiping these abominations out.

Muzan broke out laughing hysterically as he pointed at me and holding his stomach. "You claim to be the child of a virgin goddess and in such a foreign land?" He shook his head, and I knew this little conversation was over as his arm split into an abomination of flesh as it expanded into a tree with eyes and teeth upon its surface. "I have never eaten a demi-god if you are even speaking the truth but either way the end of this night will be the same regardless of what you are."

My answer was a roaring wave of flames bowling him over and I could hear him roar in pain an rage as the flames were dispersed by both sonic waves of Muzan's mouth holes dotting his monstrous form and the bladed whips spinning around his body which I had to jump into the air to dodge and as Muzan tried to strike the area he expected I would land I could only laugh as my rocket boots shot me over his whips allowing me to fly past him and carve off his mutated arm.

"This is nothing, you human!" Muzan roared and it was true as despite my black flames obviously slowing down his regeneration it still couldn't stop him simply reattaching his split arm with his other arm.

'Let's see how strong my flames will be at their highest setting.' I thought and then flipped the mental switch for my magic overload skill and then my black flames turned a haunting purple which made Muzan scream in agony as pieces of him visibly started flaking off.

"I am not some run of the mill human Muzan.. But then again you got your ass rolled by Yorrichi all those years ago who was a human albeit probably the best swordsman to live upon this word." I spoke as I Muzan flew into the air and tried to impale me with his arms that he made into bone swords and even with my inexperience at sword play, I could tell he was trying desperately to minimize the biomass he was losing within my flames by becoming as small as possible.

No longer was the primarily sound of our battle the roar of my flames no it was now the clanking and noise of my space coated sword shattering Muzan's bone blades which he was using basically as spear and trying to stab me repeatedly but I also noticed a pressing issue as Muzan was obviously trying to get his blood upon or within me as his blades were constantly dripping in his blood while he was literally spitting it repeatedly at my face from his own mouth or mouths forming on his shirtless body.

"Fuck off dammit!" I yelled as one of his blood splatters hit my armor and it was only my armor's nascent intelligence sealing my chest plate of any hole's kept the clearly alive blood from wiggling into me.

Then doing something I never had the chance to do with my more weapon inclined opponent's and monsters simply didnt have the parts, I launched a flame coated kick straight between the legs of Muzan and I could feel through my metal boots, his hip/groin audibly cracking and launching Muzan a solid meter into the air from the force and as the stunned demon returned back to the ground with gravity I coated my sword in a space force as I could and with a mighty downswing I cut Muzan in half and kicked one half away preventing the wriggling worms of flesh from instantly reattaching.

I quickly bathed the closest half of Muzan's body in pure flames trying to disintegrate it, but I could tell Muzan was no longer being stingy with his biomass as the half body I kicked aside roll over and what looked like a cannon formed out of raw flesh and bone and pointed at me.

With a loud boom I was smashed more than a hundred meters backwards and through a tree as the bowling ball sized spiked ball made out of bone was launched out of the cannon and smashed into my chest plate.

"Ughhhh well on the bright side at least, I know my armor is capable of taking a cannon ball straight on and only leaving me breathless." I groaned as I climbed back to my feet and could only deadpan as Muzan being the scared little bitch he was crawling into a weird paper doorway that popped out of nowhere.

"Dammit no!" I yelled and sent the large space blade I could at the weird doorway that started to twist in midair and the volatile mixture of my space blade and the space manipulation abilities of the upper rank four Nakime's reality marble of an endless house exploded throwing dust everywhere.

Seeing the empty shredded doorway left there but no Muzan I knew he somehow got away by using his telepathic connection to all his demons and called Nakime to make him a portal to escape in as I highly doubted, I was lucky enough for him to be shredded apart in the confrontation between our space energies.

I could only sigh in frustration as I ran over to the now decrepit house from our battle and frantically throw aside the broken-down walls and debris to free the Kamado family. 'Let's just be happy he didnt decide to throw all his Upper Moons at me instead using Nakime's portals to call them from wherever.' I thought as I threw aside a collapsed door and saw Kie shielding her children.

"We must get down to the town it will be safer there." I ordered and then with Tanjiro's help I loaded the obviously traumatized family into the cart and started pulling said cart down the path we came earlier.

"Jake did you know that demon would attack us..." Tanjiro asked quietly and amid the sniffles of his family I could tell he was trying to put together a picture of what happened tonight and whether he should blame me for this somehow.

"Yes, I learned after killing another demon that Muzan the leader of the all the demons here in Japan heard about your family being wielder of the Sun Breathing Style and I wanted to save you and do my best to kill Muzan." I explained giving the perfect excuse as to why Muzan would do anything to kill his family as should he tell anyone he knew said style and ask if Muzan would go after him for such a thing, well the answer would plainly be yes.

'Well looks like I need to meet with the demon slayer corps and Ginyu coming through tomorrow will be the perfect opportunity to learn where the hell I can find Muzan and his upper rank demons to harvest their corpses.' I thought already making plans to use my new identity of a demigod monster hunter to blend into the demon corps to get info.