Night had already fallen by the time Tsubaki finished rehearsals. Watchful for any ambushes, Sasuke escorted her back to the royal palace, where she bade him goodnight and returned to her quarters, a guest suite in the palace.
As for Sasuke, he hadn't gone far; he hadn't bothered finding accommodations in the royal capital, so he was doubtless crashing somewhere out of sight; she could still feel his presence close by when she closed her eyes.
In any case, Tsubaki wasn't ready to sleep just yet. She summoned Katsuyu to keep watch over her room while she went to fetch some glass bowls from the kitchen, which she delicately placed on the living room table upon her return.
"I just don't know what to do, Lady Katsuyu," Tsubaki sighed as she began sorting the bowls. "Do you think I should call for help? If I fall and Orochimaru takes my body again, and Sasuke dies because of me, it'll be a disaster…"
Since there were once again two Shikkotsu Forest contractors in Sakura and Tsubaki, the reverse-summoning shuffle was now possible again. Neither woman had told Sasuke yet, but Tsubaki had received tacit permission from Sakura to summon her to Redaku in case of an emergency.
"That's not all there is to it, is there?" Katsuyu chirped softly. "You're hesitating to call Sakura for help because you wish to prove yourself."
Since Tsubaki possessed part of Sakura's memories, she could remember being all-powerful.
Even though she had previously existed in a state of waking dream, she was still a Sakura variant, yet without rhyme or reason, she had abruptly found herself inhabiting a far weaker body. That wasn't to say she was powerless; her body had not been Ōtsutsukified, but it still possessed an array of powerful Kekkei Genkai and remained vastly superior to the majority of shinobi bodies… but even so, the transition had been jarringly shocking.
"I have my own feelings, my own pride… and now, I'm even making my own memories, so I should be my own person," Tsubaki muttered. "But for some reason, I can't help but feel… robbed."
"You never asked to be born, but then again, the same goes for every living being too," Lady Katsuyu said with a little melodious laugh. "I suppose the question you must ask yourself is whether you are confident that Sasuke and you can handle the current situation… and whether you are allowing your pride to blind you to what must be done."
The situation was especially precarious, as Sasuke was dangerously low on stamina and could not fight at full capacity. Tsubaki had only just begun to grow accustomed to her new body's baseline capabilities thanks to the play rehearsals, but she was not yet confident she would be of much help in an actual fight against S-rank missing-nin. It was like trying to run in clothes that were far too tight for her.
"Sakura is busy negotiating with the Land of Fire's elite, we can't disturb her," Tsubaki said decisively. "I'll show her what I can do… I may only be worth fifteen Kakashi in her eyes, but our brains have the same specs."
Katsuyu watched in interest as Tsubaki placed her hand over one of the glass bowls and started producing wood shavings using Wood Style nature transformation.
"What are you doing?" she asked curiously once the bowl was full.
"Making high explosives," Tsubaki replied. "Unlike Sakura, I can't use Strength of a Hundred — Creation Rebirth, so I can't go full meathead mode and go around punching people with explosions. I'll get hurt."
And since Sakura was a cheapskate who thought buying shuriken, kunai and explosive tags was a waste of money, she hadn't bothered giving Tsubaki anything but the clothes on her back before handing her over to Sasuke… the rationale being that if Tsubaki wanted weapons, she'd make them out of crystal.
"Do you know what kind of acid you produce, Lady Katsuyu?" Tsubaki asked casually.
Land slugs didn't generally make any kind of acid, but Katsuyu could, and if she was anything like the common sea slug…
"It should be sulphuric acid, I think," Katsuyu said thoughtfully.
Incidentally, human stomach acid was hydrochloric acid, but short of cutting open her stomach, Sakura wasn't getting any of that, short of dumping a bunch of table salt into a bowl of Katsuyu's sulphuric acid.
Not that she needed to for this particular science experiment.
"Excellent, just as I thought! That'll save me some work," Tsubaki said, beaming. "I'd nicked some fake jewellery from the theatre's costume storage just in case, but it seems that wasn't necessary after all… I guess I'll return the props to the costume department tomorrow morning before anyone realises they were gone."
The fake jewellery was made out of iron sulphate; pyrite, better known as fool's gold. Had Lady Katsuyu's acid not been sulphuric acid, Tsubaki could have obtained some by cooking the metal in an airtight Earth Style jar in the fireplace and collecting the resulting juices.
"Vapour Style mists are primarily composed of nitric acid," Tsubaki went on. She pursed her lips and spewed a thin stream of clear liquid into a different glass bowl. "One hydrogen, one nitrogen, and three oxygen atoms…"
Only Yin-Yang Style could create matter ex nihilo by performing energy-to-matter conversion.
For anything else, the basic elements had to come from somewhere, that somewhere generally being the air. Though a talented Water Style user might make it appear as though they could create water out of nothing, they were either drawing moisture from the air or making their chakra behave as though it were water, the latter being vulnerable to ninjutsu absorption and the former immune.
Using Vapour Style, which Sakura had stolen from Terumī Mei, Tsubaki could synthesise nitric acid by pulling the necessary elements directly from the air in her lungs. A byproduct of Vapour style was hydrogen peroxide, which, when combined with most acids, often produced a less acidic but far more dangerous solution.
For instance, sulphuric acid and hydrogen peroxide together produced the highly corrosive piranha solution.
Very dangerous. Very oxidising. Wow.
"Now, nitric acid is a very special acid," Tsubaki explained. "If you combine it with hydrochloric acid, you get aqua regia, which can even dissolve noble metals such as gold or platinum… but if you combine it with sulphuric acid, you get something very special indeed…"