The divine technique came to mind as he lay there looking at his new body, or rather 'she' looked at 'her' new body.
Its contents firmly cemented within her mind.
Its name came to mind as she thought about it; 50 changes to become a Witch.
The 50 changes contained different ways of reinforcing, strengthening, and getting rid of limiters of the body; in the oldest legends witches were known as one of the strongest races, comparable to dragons and phoenixes, which upon birth would already be just a step away from godhood, it was also the most mysterious race, known for their supreme control of the laws of worlds as well as their undying bodies strong enough to take several hits from other races with higher cultivation than them.
But back to reality; she lazily swept her gaze across the room taking note of a few distinct features. The room contained little; a table with a chair, a bed, and a wardrobe. The whole room consisted of wooden or stone fundamentals and walls, with dark tinted wood furniture, very simply built with little to no decorations, she went up to the wardrobe wanting to get dressed but found only 3 sets of nun clothing. Her pupils constricted at the scene as she muttered "Fuck,".
A while later she had somewhat clumsily managed to dress, proceeding outside she saw another nun who looked towards her with curiosity turned horror at the disrepair of her garments, noticing the gaze of the nun she said "sister, do you mind helping me a little?" As she smiled innocently.
The other nun looked towards her in disbelief and muttered "sure... overseer you need to dress properly or rumors will start circulating...» somewhat surprised at the new information, she looked at how this sister dressed her robe and corrected on a few pieces of her garment to resemble it as well as she cared to bother. "Thanks, sister, that's all I needed." being a nun meant she had a lot to do to maintain the monastery, not to mention she had her laziness to deal with as well.
Having gone through the motions with the monastery she managed to gather information about herself and her situation; she was one of the five overseers of the Monastery and a noble lady sent here to repent for her sins, her name was... is Vesta and her now disowned family name was Luminem, though that wasn't important.
Seeing so many innocent girls around herself triggered her origin of sloth enhanced instincts, wanting to corrupt them to laze around instead of working diligently.
However, being a demon king meant she had a resolute and hardworking attitude that had been ground down by sloth when she cultivated it to such a high level. Knowing what sloth would do to her right then and there, she decided to cultivate the witch technique first and get out when she had the power to.
Having thought about it; a body cultivation technique suited her just fine, considering her lazy habits. Thinking up to here she sat down and thought of the first level of body refining she had to do, she pulled on the inherent power in the air and layered it over her skin, and stopped breathing.
Being a demon king meant having a whole world in your back pocket, which obviously resulted in having lots of different knowledge as well as wealth, and techniques, however, he knew of no other body-cultivation technique that would start by getting rid of the respiratory system or even get rid of it at all, but this was just one of the requirements to start using the witch body technique.
She, of course, couldn't just up and stop using it though; she needed to first make her skins ability to 'breathe' so strong that she wouldn't need to breathe with her lungs, by exiting her skin with qi while depriving her lungs of oxygen, slowly improving that ability to breathe without lungs.
Even finishing this preparatory stage took a few months without the right resources to help, but once complete, she would be able to start remodeling her lungs and blood, in order to make them absorb the inherent qi in the air to strengthen her body rather than worry about oxygen, once fully remodeled she wouldn't even need oxygen and would be able to breathe and stay alive as long as she had qi, this, of course, meant she couldn't live without qi, but the technique would fix that problem as well later on.
The final stage of the lungs' preparatory stage would be to make her skin breathe qi as well, instead of oxygen. Making her respiratory system into an automatic qi-gathering system.
Having remodeled her respiratory system; next up on the list was her heart, another dangerous remodeling attempt later a crystalline heart of qi stood completely still where her heart should have been, and it wasn't pumping, but she was still alive and well; the heart created a constant turbine-like flow of blood which didn't pulsate like her past heart, the next step?
The blood vessels, having remodeled her heart this step was pretty dangerous since popping one blood vessel would sprout a constant stream of blood 'til she was empty; so it slowly but surely tempered and optimized the positioning of blood vessels, removing easily exploitable vessels like the carotid artery from the vicinity of the skin.
It also made the vessels more flexible and replaceable with spare blood vessels going to places and taking up the job if the main blood vessel was damaged, this, as well as the placing of small contractable blood stopper muscles at different convenient spots around her body, made bloodloss a non-issue if she was severely damaged.
Having done all of that she began creating another crystalline heart on the right side of her chest mirroring her left heart, effectively making sure she cannot die even if one of her hearts fail. And like that she would continue to improve or otherwise remodel her own body for a year, while not raising suspicion within the monastery she worked.
"Haah and that's the tendons done..." having gone through the remodeling herself she knew just what kind of pain it brought her, but compared to some body-cultivation techniques this was nothing... if you don't consider that this was merely the preparatory phase that is.
Therefore although worried, she knew the effects of just the remodeling required to start cultivating the witch-body technique.
But this remodeling did have its downsides as well.
"Did you see vesta recently? Her skin is pale white like a ghost and her hair looks like it was dipped in blood?" having moved blood vessels away from the immediacy of her skin, she appeared pale and sickly to others, not to mention the toll the remodeling took on her body; a few weird changes happened to her appearance as well, the brown-turned-blood-red hair one of the more noticeable differences, along with loss of general and pubic hair around her body except her hair and eyebrows. For even the sweat you'd normally have as a human had been removed because she had increased her innate resistance to hot and cold to a degree where casual weather couldn't affect her anyway.
But it eventually caught attention and a few rumors began spreading, hearing of these rumors Vesta began planning her escape.
Actually, it wasn't a plan but more like a get out-rob some clothes- and get a job to sustain food unsuspiciously kind of deal, having been a being of sloth, she didn't put too much thought into it and just jumped out of the monastery and began walking the road looking for women's clothes that she could steal; having changed the way her muscles work she was still a bit weak but would be able to become exponentially stronger without even outwardly showing any overwhelming muscle, it took time to develop those muscles though, which meant she needed to carefully pick her opponent before trying anything.
Having decided to do so she snuck into a closeby farm and ambushed the housewife in her own home after silencing the farm animals, she picked this farm because she didn't see the farmer anywhere close-by.
She picked up some loose clothing and dressed up while ignoring the rough texture of the cloth. She also scavenged some food and killed the wife so she wouldn't act as a witness, having done all that she sighed while leaving, how did she fall so far? But it would be worth it in the end; even phoenixes become stronger after rebirth after all.
She wasn't particularly beautiful or ugly, but her pale skin and red hair would attract unwanted attention, so she had prepared a cloak and hood for the journey. Having reached a small village she went around looking for some sort of job she could fulfill to earn her food and shelter, after looking around she found a place in need of a shopkeeper, which she gladly took after calculating her needs according to the salary and amount of work.
Getting into her daily routine she began to cultivate the first of the witch-body technique of 50 changes.
The brain optimization stage.
Being a demon king she was pretty intelligent in the first place, but what she didn't know was that intelligence and memories are stored in the soul, the brain would only be the conductor of the soul, and an inefficient brain could limit the potential of the soul as well as the body, so a few optimizations had to be made; most just getting rid of certain useless or suboptimal parts and replacing and remodeling the remaining parts making the control of the body and the perception of senses so detailed and fast that the soul in most cases wouldn't be able to catch up.
Frighteningly, playing with the brain was one of the least dangerous practices of the witch-body technique, but having only body-cultivation would make one unbalanced, so, having cultivated the law of sloth to almost ascendancy before; she decided to cultivate it again this time as well, though this time, slightly differently, having learned from her mistakes in her past life she sought to perfect her cultivation path, and having the experience of a demon king certainly helped.
There were 10 cultivation realms before one reached godhood and breach the veil, or that's the theory anyway, she personally had never seen anybody reach the tenth realm or 'breach the veil', even Lucifer was only a ninth-realm upper-stage cultivator when he tried to ascend the first time. Each realm has approximately three inner stages describing their accumulation within that stage, simply termed upper, middle and lower stage.
Personally, Belphegor had been a ninth-realm lower-stage cultivator at the point of his death. But at the eight realm upper stage you are already considered so powerful that if others want you to die they'd have to sacrifice a peak existence or several just to succeed.
Her previous realm accompanied with her previous knowledge allowed her to start fast, having reached the early stages of the first realm within a month.
And the late stages within two, for someone as average as the original owner of her body doing this alone would probably take years if not decades depending on the resources she could get, but with the preparation for the witch-body and the knowledge and experience of the demon king this took around two months even without resources readily available; especially since she could absorb the diligence, dedication and passion of others around herself to strengthen her soul and further her cultivation, leaving the people around her lazy and sleepy.
But she also needed to be careful, if it was noticed by someone she would be hunted down for using demonic/dark arts.