Invigorated by her surprising success at communicating with the Sound-nin kunoichi, which had yielded the promise of Kin Tsuchi teaching her Genjutsu, Sakura decided to try her luck with Orochimaru next.
'System, can you conceal all knowledge of the future and of whatever I wouldn't be supposed to know while I'm interacting with Orochimaru?' Inner Sakura asked pre-emptively. 'Just to be safe.'
Sakura withdrew her mental tentacle from Tsuchi's wispy green chakra, and directed it towards the glassy orb, around which a white snake was coiled. Upon making contact, the dark void of Sakura's meditation space, in which the colourful blobs of chakra were suspended, was abruptly drawn into a single point, as if the fabric of Sakura's inner world were a plastic bag that had been accidentally sucked into a vacuum cleaner.
Blinking, Inner Sakura suddenly found herself in a dimly lit room, illuminated only a transparent vat full of glowing green liquid. Glancing around, she found the room to be completely devoid of signs of life, save for the bubbling vat, in which a body was suspended.
'Hello?' Inner Sakura called out. 'Orochimaru-dono? Are you there?'
Left with no other choice, Inner Sakura slowly inched forward, towards the person suspended in the vat of liquid. As she approached, Inner Sakura was drawn to the exquisite beauty of the woman's breasts, which were bobbing gently in the dense fluid. Entranced by their perfect shape, it was only at the last second that Sakura would notice that the body possessed her face.
'GYAAAH!' Inner Sakura screamed.
Suddenly, neon lamps blinked to life, flooding the dark room with light and forcing Inner Sakura to shield her eyes momentarily to avoid being blinded. Upon opening her eyes again, she found herself in what looked like a laboratory; test tubes, beakers, dissected specimens lying on tables, pallid organs floating in jars of formalin…
'Please, make yourself comfortable,' came Orochimaru's voice behind her. 'You came here hoping to learn Jutsu, correct?'
Inner Sakura spun on her heel, coming face-to-face with Orochimaru, who was currently in his handsome form. That is, he was wearing a normal lab coat, and he wasn't doing any weird stuff, like pretending to be a Rokurokubi by extending his neck, or doing anything else off-putting in that same vein.
'That's right,' said Inner Sakura cautiously. 'You'd be willing to do that for me?'
'I wouldn't need much in return,' Orochimaru chuckled. 'Perhaps a favour or two, once in a while.'
'Nothing like killing the Third Hokage for you, right?' Inner Sakura said, frowning.
'I wouldn't want to deprive my original self of the pleasure of squeezing the life out of the old man,' Orochimaru laughed. 'No, nothing so difficult…'
There was no such thing as a free lunch in any of the two worlds she had known, so Sakura was highly suspicious of Orochimaru's offer. However, the idea of having one of the Legendary Sannin as her personal tutor was highly appealing to her, even with strings attached…
'Do you know Senju Tsunade's Chakra Enhanced Strength?' Inner Sakura asked. 'Or the Rasengan?'
'You're not going to ask about any of my Orochimaru-style Jutsu?' Orochimaru asked curiously. 'Ah, I see— you do not trust me yet.'
'It's not a question of yet; I don't trust you AT ALL,' Inner Sakura fired back. 'Don't forget, our chakras are linking our spiritual energies— I can feel your greed for my body.'
There could be no falsehoods in Sakura's mind palace, but that went both ways; Sakura and Orochimaru could both feel out each other's true intentions while they were connected in this fashion.
'And yet, you're still asking for my help,' Orochimaru pointed out. 'You believe that you can somehow use me and still retain your body.'
'And you believe you can lead me along,' Sakura countered, 'and turn the tables on me at the last second and take possession of my body.'
If Sasuke had escaped the fate of being Orochimaru's host body, why couldn't she? Besides, she had the System's help, and Orochimaru was only a bit of chakra stuck inside her chest…
'Very well, it seems we have come to an agreement,' Orochimaru hissed. 'I shall teach you what you want, and you shall grant my small requests, every once in a while.'
'To jolly cooperation, then,' said Inner Sakura, extending her hand, and they both shook on it.
Orochimaru could already guess what Sakura wanted, based on her questions and their spiritual connection.
'To answer your question, I do know the principles and the training method for Chakra Enhanced Strength, but I do not know the specifics behind the Fourth Hokage's Jutsu,' he began. 'I was once the Slug Princess's friend and comrade, but I wasn't especially close to Minato.'
'While the Rasengan is the peak of chakra shape transformation, which is in itself a direct application of chakra control, Chakra Enhanced Strength could be considered the peak of chakra control as a whole,' Orochimaru continued. 'The Fourth deemed the Rasengan to be an incomplete Jutsu, missing only nature transformation. Therefore, I assume that you also wish to take Chakra Enhanced Strength to the peak of Nintaijutsu by incorporating chakra nature transformation, correct?'
Inner Sakura nodded with shining eyes.
'Such a thing has never been done before,' Orochimaru admitted. 'There is the Hidden Cloud's Lightning Chakra Mode, but that is a Cloak-style Nintaijutsu; or in other words, a continuous effect. The secret to Chakra Enhanced Strength is to make one's chakra explode outwards in an incredibly short and precise burst the instant your fist make contact with your enemy. The elemental mastery you would need to perform nature transformation in that split instant is staggering, but it should be possible, maybe…'
According to Orochimaru, to use Chakra Enhanced Strength, Sakura had to coat her limbs in chakra, and then make that chakra spike out in an incredibly short burst the very instant she made contact with her target. Short burst meant extreme speed, and extreme speed meant unstoppable force.
But to incorporate nature transformation on top of that… To Orochimaru, it didn't seem like it would be worth the effort; both training-wise and concentration-wise.
To put the difficulty into context, Elemental Chakra Enhanced Strength would be like being asked to complete a two-hour-long calculus exam in under five minutes, while balancing on a unicycle, and without making any mistakes…
As for Lightning Chakra Mode, it would be a little bit easier; you would still have to complete the two-hour-long calculus exam on a unicycle without getting any answers wrong, but you would have the full two hours to complete your exam. And also, you would have to pedal your unicycle up a steep incline.
'If you could just lend me your body, I'm certain I could find a way to simplify it in under five years,' said Orochimaru, licking his lips hungrily. 'I do not have access to my full research capabilities while I'm in here…'
'In your dreams,' Inner Sakura snorted.
'In that case, you must first get used to the regular Chakra Enhanced Strength, and you must also get used to changing your chakra's nature. Be warned, it often takes even the most talented shinobi years to achieve nature transformation...'
When Sakura opened her eyes in the real world at last, she had obtained one-and-a-half Wind style Jutsu from Orochimaru (Wind Style: Breakthrough, and the way to apply chakra to a sword), and obtained an auditory-type Genjutsu from Kin Tsuchi.
Having learned how to turn her chakra's nature to fire in under five minutes with 200% affinity, Sakura wasn't especially worried about having to learn how to change her chakra's nature to wind with 175% affinity!