After opening a window just in case, Tsubaki held up Katsuyu with both hands and had her slowly squirt her odourless sulphuric acid spit into a glass bowl. She then carefully and very slowly tipped in the acrid-smelling nitric acid, mixing them together through chakra manipulation. The bowl began rapidly heating up as the two colourless acids swirled into one, and a few tense minutes later, the solution had turned a faint yellow.
Thankfully, the glass bowl was still holding strong!
Breathing a sigh of relief, Tsubaki dried up the wood chips she had previously made by exposing them to Scorch Style chakra. Once she was satisfied with their water content (or lack thereof), she dumped the shavings into the mixture.
"We now have a way to introduce nitronium ions, that is, nitro groups, to basically anything we want," Tsubaki explained. "But since I only have wood on hand, that's what I'm using."
The razor-thin slivers of wood began soaking up the solution, but otherwise, nothing particularly exciting was happening, visually speaking.
"If I had some glycerine, I could make some nitro-glycerine," Tsubaki went on wistfully. "It's a bit late to be shopping for skincare products, though…"
By incinerating sodium-rich plants like seaweed, Tsubaki could make soda ash (any old plant ashes wouldn't work, as one would obtain potash instead). By combining the ashes with quicklime, which she could very easily make using Lava Style: Quicklime Jutsu, she could then obtain lye; that is, caustic soda, or sodium hydroxide. To obtain glycerine, it was then a simple matter of finding any fresh corpse and attacking it with the caustic soda, converting its fat into soap and glycerine.
"Mix in the acid mixture from earlier, and boom!" Tsubaki said, laughing. "Corpse Explosion Jutsu!"
"That's… a bit macabre," Katsuyu commented.
Had Tsubaki thought to buy some specialised cleaning products during the day, she could have mixed ammonia with nitric acid to make an explosive more stable than nitro-glycerine, but as ammonia was rather difficult to synthesise without the proper equipment, she could only give up.
The bonds of airborne nitrogen were quite tenacious, after all… but that was exactly what made unstable nitrogen so good at violently exploding.
"In any case, what we're making today is pyroxylin… homemade nitrocellulose," Tsubaki explained. "The nitro groups attach themselves to the cellulose polysaccharides in the wood and boom, we've got ourselves DIY explosive tags!"
Moving things along, the jutsu formula painted on each paper bomb was actually a fūinjutsu, which had two very important purposes:
The first was that sealing prevented the tag from being triggered too easily: chakra wasn't the energy source; it was the detonator. Otherwise, why would anyone even bother with Explosion Style if they could just make their regular chakra explode?
The second was confinement: just like gunpowder, nitrocellulose would simply burn up rapidly when exposed to heat. The seal contained the chemical reaction, incarcerating the rapidly expanding hot gases and causing pressure to build rapidly, thus producing the desired deflagration when the blast was finally released.
"There's nothing nitrogen hates more than being in a relationship with anything but itself," Tsubaki continued. "When nitrocellulose is ignited, it spontaneously and violently combusts using its built-in oxygen supply to form carbon monoxide, carbon dioxide, water and nitrogen gas, producing a detonation four to six times stronger than black powder!"
Basically, the nitro group was only very loosely attached to the cellulose, and the nitrogen yearned for incest, wanting to form one of the most stable molecules in existence: nitrogen gas, with its two nitrogen atoms joined by a triple covalent bond. The formation of such an incredibly stable molecule released a massive amount of energy… thus, kaboom.
Only a few special plants, bacteria and mushrooms were capable of breaking down N2.
"And now, for the cherry on top," Tsubaki said, grinning evilly as she retrieved one of the finished products with a pair of chopsticks. "How very devilish of you, Senju Tobirama… no war crime is beyond you!"
Mutually Multiplying Explosive Tags were inscribed with a slightly different fūinjutsu from regular explosive tags. Within each paper bomb was sealed another two, and within each of those were sealed yet another two, and so on, like exponential Russian dolls. One becomes two, two becomes four, four becomes eight, and so on and so forth, until the opponent has been reduced to nothing but a smoking crater.
Of course, this meant one needed to make absolutely certain the first tag found its mark, or it would have been a massive waste of time nesting each tag within another; hence the Shadow Clone Jutsu into Flying Thunder God Jutsu combo to ensure it stuck to the right person.
However, Sakura was not only cheap, but she was also a bit lazy.
Smart, but still lazy.
Being a clone of Sakura, Tsubaki had neither the time nor the patience to spend thousands of hours sealing paper bombs inside other paper bombs. So instead of filling the sealing space with other paper bombs, she simply sealed some of her Explosion Style chakra inside for added oomph. With the help of a few Shadow Clones, she was done painting the formulae on her flat, paper-like wooden chips within the hour.
…
Inhuman screams echoed faintly through the side passage that led from the palace's entrance hall to the catacombs, drowned out by the moaning and the wuthering of the wind rushing through the underground. The deeper into the mountain, the louder the cries grew, until at last one reached the lowermost layer of the catacombs, where a motley group of people had assembled…
"My master was promised an immortal army," a man said, hardening his voice despite his fear. He wore a hood, shrouding his face in shadow. "I demand to know why you are wasting his valuable time by cowering down here. It's only a matter of time before the disappearances of some of my inmates reach the king's ears."
Large dinosaur bones were strewn across the floor; the hooded man had almost tripped on one when he had entered the research chamber. He ignored the moaning men and women chained to the walls and looked his interlocutor dead in the eye. He couldn't afford to show weakness of any kind.
"I am still improving upon the jutsu," Orochimaru, for it was none other than he, replied silkily. "Redaku's ancient reincarnation jutsu and my Impure World Reincarnation Jutsu both have their merits, but the ways they incarnate a soul into a body are completely different…"
Orochimaru hadn't changed the slightest bit since the last time the hooded man had seen him, as though he hadn't aged a single day since their last meeting, decades ago… His off-putting golden eyes glowed faintly in the gloom, his unnerving pupils slitted, just like a cat's… or a snake's.
"And the dragon bones dug up from the observatory?" the hooded man said accusingly. "Do you have any idea how costly it is to transport—"
"Redaku is a land of peace… reincarnating even your best warriors would be a waste of everyone's time," Orochimaru said smoothly. "That is why I changed the reincarnation target to your country's abundant and undoubtedly ferocious dragons…"
Aeons ago, dinosaurs walked the land, until some kind of cataclysm of alien origin annihilated them all at once… something far older and stronger than the so-called progenitor of chakra, something akin to a god.
As millions of years passed, the tectonic plates shifted, and the lowlands and marshlands where the dinosaurs were buried were raised into mountains… and it was in such a place that Orochimaru quietly conducted his true research, all the while improving the Edo Tensei with the secrets hidden deep beneath this land.
"In any case, it's your side that has been neglecting its end of the bargain," Orochimaru said, rising to his full height. "Shinobi from Konohagakure have been snooping around the capital, and one of them has already begun investigating the catacombs… the pink-haired girl. I would have you bring her to me… my subordinates will assist you."
"And the other one?"
"He is too dangerous for us to handle, his ability counters mine the most... it will take some trickery to separate him from his companion."
The hooded man turned to leave, his glasses glinting in the flickering torchlight.