Mahito sighed as he walked around the sewers where he had been born.
It was a sprawling network of rusted pipes and a literal river of sewage, the underbelly of a city bursting with life above.
Thankfully, some parts of the Sewer were no longer in use, especially older ones, those that were closest to the subway stations.
Those forgotten pockets of darkness made for a surprisingly ideal base of operations.
Mahito was thankfully not repulsed by the smell. Many curses seemed to gather in those abandoned tunnels.
And they served him quite well.
"Hmm, how shiny~" The blonde curse muttered to himself as he held up 3 small, pearl-like objects in his hands, allowing them to glisten in the dim moonlight that breached the grates above him.
'Transfigured fly heads... Pretty weak individually, maybe even more so than humans... But the sheer number one can find?'
He had nearly a hundred of them already. Tiny marbles nestled within makeshift flesh-pockets inside his body. Those pockets could shift freely, opening anywhere on his skin as he pleased.
Each marble within his makeshift storage held a small curse.
Individual concerns that bordered on fear, small misunderstandings that grew into hatred, even the slightest petty, negative feelings from civilians, would manifest into such insect-like curses.
They were weak, not even considered Grade 4. But to Mahito, they were a good confirmation of what he had wanted to learn.
'Curses, no matter how small, all have a soul...'
Fly heads were maybe even more fragile than the regular human, but combining them with Idle Transfiguration could theoretically lead to a stronger Transfigured Curse that Mahito could control.
And that was his goal.
'Let's try and build a subordinate for now...'
He started small, ten fly-head souls, he moved to mould them together into the shape of a humanoid figure.
It was a tall and burly humanoid curse, only a head shorter than Mahito himself.
Two large bug eyes, a gigantic set of insect wings, and a mouth filled with strangely human teeth. It was brown in colour, with different shades of it littering its body; each shade seemed to be representative of at least one fly head.
Its body was mostly covered in strange protrusions and exoskeleton-like shells. It had two sets of hands, one more ant-like, ending in what seemed to be sharp blades, while the other appeared strangely human.
"I think I'll call this a... Fly Soldier? Sounds fair en-"
Mahito didn't even get to finish his sentence before his construct blew in his face, scattering pieces of cursed flesh all over the place.
"... Right. That was a thing."
Forcing a soul far beyond its original shape, reshaping it into something entirely new, that much strain could make it collapse inward.
It was the same for combined souls; well, combining them made things even more unstable due to Mahito's inexperience.
'The souls seem to be rejecting each other a tad too much to keep such a shape... I should at least try to shape them individually first.'
So, when he touched the next marble, he tried to make something simpler... A sword, more like a cutlass in shape, with the fleshy handle perfectly moulded to his hand.
It was simple, almost too natural, and swinging it felt nice too.
The Special Grade Curse left a long and deep scar on the wall in front of him with a single swing.
He felt as if he could entirely rip that wall apart if he wanted to; his strength, as a Special Grade Curse, far outshone a vast majority of that world's sorcerers.
The blade itself seemed to still be sturdy and sharp, and it remained stable for at least 10 seconds.
Mahito could feel its structure losing strength beyond that point, so he threw it to the side, allowing it to explode into dozens of small, steel-like bone shards.
Some shards hit him, but as they didn't damage his soul, they could easily be ignored.
'Some hints of dull pain are felt... But it seems that as long as my soul isn't damaged, I won't be in too deep a pain to hinder my movement.'
He remembered Mahito constantly flinching and feeling hits from even the likes of Nanami Kento.
Nanami might've been a strong Grade 1, but he lacked a true understanding of the soul. His blows never truly hurt Mahito, not where it counted.
But as a newborn curse, Mahito was not used to pain when facing him. Even the dull pain from those purely physical hits was enough to make him flinch and recoil.
It was at least a large enough distraction that he was left open to hits from Sukuna's Vessel, Itadori Iuji, who could damage him.
'If I were to face the two of them as they were in the show, then I think I'd be able to win easily enough...'
He had the battle experience, he had the critical thinking required in such moments already trained to an extreme. He only needed experience with his technique, all facets of it.
Mahito also closed his eyes as he manipulated his body and expelled all of the shards that had pierced his body.
It felt natural, manipulating his body. He felt in control of every single strand of hair, every single muscle.
With a smile, he slowly clenched his fist and turned it into a meter-long curved blade
'This one feels a lot sturdier...'
With a swing, the blade extended, his wrist unravelling into a fleshy chain. It struck the wall with a harsh crunch, cracking stone and blasting dust into the tunnel.
'Speed is a bit lacking, but I can work on that as I grow.' Mahito calculated that his strike was fast enough to take a Grade 1 Sorcerer by surprise, but anything above that could easily outclass him.
As a recently born curse, Mahito had boundless potential ahead of him.
'First thing I should do... Learn how to manipulate souls better, see what clicks. I should also see just how far I can take my own soul's manipulation...'
He had a long road ahead of him, but at the same time, he had quite a few weeks at his disposal.
The first thing he focused on was figuring out just how souls resonated with each other.
He quickly discovered that he had been stupid to expect himself to create a 'Fly Soldier' on his first try.
The souls of the fly heads were weak; They had little to no resistance when being meshed together. He had just been far too hasty when pulling all of the souls together.
He tried again. Slower this time. Fusing them one by one, letting the bonds form naturally, adjusting to the rhythm of each soul's resistance.
He also wanted to later on compress them into smaller forms, so that he could carry the combined souls around freely.
It was technically possible if the souls resonated enough, or if he found some way to forcefully bind them.
Shaping them was easy, it only took imagination. But doing it by force? Wasteful. Even if Fly Heads were plentiful, gathering them was still a chore.
Mahito had spent an entire day wandering the sewers. He gathered Only around a hundred.
But that was enough for him to play around with for a while.
'Let's start working towards it... A small personal army that I can keep in my pockets~'