NOTE: Bold Words means Conversation, I did this so readers/viewers will not get confused of the text. Sorry for doing this right now because this idea in my mind only came up today.

A demon was watching them from above, walking at the thick web threads in the skies, with cold face he says "don't disturb my family's peaceful life. Either way, all of you will die here..."

The demon continue to walk away at the skies using the thick threads while ignoring them.

But Inosuke was taunted as he don't like the demon's behavior. He leaps high in the air attempting to follow the demon.

"Where the hell do you think you're going? Fight me! Fight-" Inosuke paused as he was stopped by Saitama.

"Oi, don't rush yet, that demon was up to something, let's save these kids first before we engage a fight with that demon" Saitama in his calm yet worried expression.

"Gnnnnmmm that demon looks strong that's why I need to defeat it!" Inosuke while snorting with a steam in his nose.

Back to their battleground, they were surrounded with 6 controlled young demon slayers, some are conscious and some are unconscious yet all of them are controlled by the threads.

Inosuke jumps down as he goes back in defensive stance with Tanjiro, Saitama was just watching them, he was observing the youngsters getting controlled by a demon and waits for their call.

"Can I now save those kids?? Should I wait longer?" Says the impatient Saitama.

Murata was baffled by the hero offering help, he don't believe that Saitama can do something impressive by just seeing at his nonchalant behavior.

Saitama noticed Murata's glance as he says "hm? What is it?" in his calm yet poker expression.

"Are you really a demon slayer? Or some just lost villager perhaps? Either way this is a battlefield, not a place for some civilians like you--" Murata in paused tone when he saw Inosuke raising his fist to hit him.

Inosuke smacks Murata again for insulting Saitama "dumbass!! He is stronger than you and even stronger than us! You are the weakling here and you need to go home!!"

"Grrr!! No need to hit me like that!!" Murata while hesitating to smack Inosuke back

Saitama let out a deep sigh as he shows considerate feeling towards Murata, the hero misunderstood Murata even Murata is talking to him and even insulting him.

"I understand your feelings, sometimes you piss your pants when you are scared at demons..." The caring Saitama when he misunderstood Murata's remarks.

"Noo! I didn't pissed my pants!! And I was talking about you! Not myself!" Says the pissed off Murata but Murata can't do anything about it but to let out a sigh of annoyance.

Saitama then becomes serious, his face goes detailed as he told his squad. "Kids....let me handle this"

Saitama's vein around his leg and arms bulges as he moves at great speed cutting the threads of the controlled young slayers using his short sword. He did it in microseconds.

"W-what just happened?" Murata in shock yet disbelief expression

Tanjiro smiles in relief as he says "good job mister Saitama! That was a nice and clean cut."

"Good! Now we can focus hunting the main demon controlling them!!" Says the excited Inosuke while bending down to dash off.

Murata can't believe what he sees, a baldy who just moves at a microsecond to save his fellow comrades by cutting all the threads in the blink of their eyes, his flabbergasted expression says it all.

Tanjiro looks at Murata as he says "please take care of them, we will deal with the demons!"

Inosuke and Tanjiro dashes forward while Saitama in a blank expression follows around in their back.

The taunted Inosuke races with Tanjiro while saying "gnnnm, no way I will let you slay those demons! I will be the one who will slay them!"

Saitama who is following in their backs says "hey, we are not playing a game here..."

When they run at miles away, they saw a female demon slayer controlled by a thread.

The female demon slayer was sobbing, tired and was moving from the thread's action. She begs to the squad to stay away from her.

"Please...don't come closer, I am controlled by a demon! Otherwise, I'll end up killing everyone!" Says the sobbing and terrified youngster.

Tanjiro and Inosuke can see that the girl killed her fellow comrades because she was manipulated and controlled.

But the controlled girl suddenly dashes forward to attack Tanjiro and Inosuke. Her movements is so fast that even Tanjiro and Inosuke has a little trouble of saving her.

"S-stay away...!" The controlled girl yell while trying to stop herself in hurting them but it was futile.

The detailed Saitama who is no longer being a carefree, saves the girl by moving at time stop speed and cutting the threads in a blink of her eyes. Saving her in the process as Saitama carried her in his arms.

The girl was shocked as she can't believe what she sees in her eyes, she was fascinated that someone was able to save her despite the struggles of Tanjiro and Inosuke.

"It's fine now, you're safe.." Saitama in gentle tone as he smiles warmly at her.

"T-thank you.....for....saving me..." Says the tired female demon slayer before she faint from Saitama's arms. Her eyes drop tears after she faint.

"She fainted because of overexerting herself, she must have gone a terrible trauma in her life by killing her own comrades in her eyes ." says the angry Tanjiro while looking down.

Inosuke was speechless as he looks down with a feeling of hatred towards the demons. Inosuke looks at them as he says "no matter what happens, we will save these demon slayer's asses!!"

Suddenly, a 2 young male demon slayers come to ambush the squad.

Their body was crippled, and they were begging to get killed infront of the squad. They were tired, almost dying and says "P-Please kill me..."

Fun Fact: Those hostages are killed in canon KNY, but in this timeline, Saitama saves them all.

The hero feels heavy in his heart seeing the youngsters' state like that, he clenches his fists and his hatred towards the demons in Mount Nagatumo suddenly increases to its peak, as if Saitama won't spare the demons now.

Saitama didn't hesitate to save them by moving at insane speed, cutting the threads using his pocket blade (short sword) before the demon's thread can react.

Saitama then puts their bodies down in a gentle manner as he says in assuring tone "don't worry kids, all of you are now safe...please rest for now until the help arrives..."

The saved demon slayers suddenly sobs and cried like "we were scared to die....why would this happen to us....!"

Tanjiro and Inosuke were just listening to them, they feel sad and angry seeing them like that. But this is a battlefield which they expect something like this would happen.

Saitama then says "just lay down and rest, the help will soon arrive.."

Saitama looks at Tanjiro and Inosuke as he then says in serious tone "let's go kids..."

Tanjiro shakes head to focus as he dashes to locate the demons while saying "no more chatter, we need to use our time before the demon can get through us!"

"Hmph! I detected that thing before you did!" Says the dashing Inosuke.

...
...

Meanwhile at the spider demon called "Mother".

The demon was angry after seeing her dolls are saved by the baldy.

"Damn! Who was that baldy!? Is he a hashira!? He manage to save those dolls before I can use them!!" Says the angry mother spider demon.

A kid like demon who was leaning at the tree suddenly visits her. His name is Rui.

"Hey, don't you think this is taking too much time?" Says Rui, who's face turns dark.

The mother spider demon has a pale face as she becomes nervous and scared seeing Rui's serious expression.

Rui continues to talk in cold tone "father will be angry at you now..."

"P-please don't tell father about this! I'll promise to eliminate them, I swear!" Says the nervous mother spider demon.

Rui turns back as he says "finish the job quickly before you get abused again..." He then disappears from her sight after passing in the tree.

"Gnn..damnit.." the mother demon mutter under her breath. She can sense that Saitama's squad is nearer on her spot.

The mother spider demon grins as she says in sadistic tone "did you really think you can get near to me!? Then how about my triumph card!"

...

Back to Saitama's squad without Zentisu.

A headless bulky demon leaps down infront of them with intimidating appearance.

"A headless demon!?" Tanjiro while going battle stance.

"Damn...how can we beat that thing without a head--- oh right the threads!!" Inosuke in a bright energetic tone.

But the hero steps in as he speed blitz the demon off, using his half sized blade while saying "power breathing, first form: normal slashes..." In a calm tone

The hero's slashes turns the demon into a dust particles, while the dust around got blown from his shockwaves. Tanjiro and Inosuke were pushed back a little from the wind.

"Ehhh??" Tanjiro in forced smile with awkward expression

"Ah right! we forgot we got some mountain slasher here...kwahahaha~!" Inosuke while laughing in bold tone

Saitama looks at them with poker face as he says "let's go, we got no time..."

"Y-yes!" Tanjiro nodded as he dashes to the demon's location.

"Gruuwaahhh!" Inosuke follows Saitama and Tanjiro around. Inosuke was leading and gesturing them the demon's location.

Tanjiro can sniff the scent of the demon, he suddenly leaps high in the air using the trees as a stepping ground as he can sense the mother spider demon at the distance "there! I found the demon!!"

Tanjiro swirls around as he goes down to lunges himself towards the shocked demon. Tanjiro gripped his sword tight as he is ready to decapitate the demon's neck.

"Impossible, how can they kill my toughest doll....at this rate... he'll kill me! He'll cut off my head!!" In scared tone of the Mother Spider Demon, she can't do anything like escaping since Tanjiro is now so close at her range.

Tanjiro breathes heavily, gripping his sword tight as he goes down in the air cutting the demon's neck.