Chapter 18

**Sorcery Showdown** (妖 (よう) 術 (じゅつ) 決 (けっ) 戦 (せん) , *Yōjutsu Kessen*) is the eighteenth chapter of the Dr. Stone manga.

## Summary

Kinro and Ginro are still attempting to battle the soap bubbles blown by Senku. The latter of the brothers eventually gives up and opts to use his personal special technique: running away and letting it be someone else's problem.

As he's leaving, he spots the perfect candidate to take the burden, and thus Chrome makes his debut; Kohaku mentions it's good that he showed up, as it saves them the trouble of searching for him.

Chrome boasts about being a very smart genius sorcerer, and calls out the brothers for being scared of such crude sorcery, explaining that he can make as many bubbles as he wants from charcoal lye. This remark catches Senku's attention.

Kinro states that they weren't scared, just cautious; Ginro admitted that he was actually scared. Never the less, Chrome defends that he won't be upstaged by an outsider, and challenges Senku to a sorcery battle.

Under the argument of not getting the village caught up in this ''battle'' they move over to a clear area of the forest, where Chrome's storage shed stands. He asks his audience to wait outside as he rushes in to retrieve something. It becomes clear the change of location was just so he could access his equipment.

He lights up a large campfire and tells everyone to stand back as he does what he calls ''Rainbow Bridge''. The fire starts bursting into a myriad of colors as he tosses mysterious powders into it. Senku however sees though this play, and points out it's a flame test reaction, starting to enumerate the chemicals Chrome tossed in.

Expecting Senku to either submit or run away in fear, Chrome struggles to keep his cool. He runs inside and comes back with a spherical object he frantically rubs with his hand. Almost out of breath, he reaches to the tip of Ginro's nose with his finger, and he jumps back in shock, saying that it hurt.

Senku takes this item from him and identifies it as a ball of sulfur, even being able to tell how Chrome crafted it, which he finds pretty ingenious. He also praises his discovery, as the sulfur ball electrostatic generator was not invented until the seventeenth century. However he then questions why rubbing it with hands when leather works much better, which he tries with his science flag while standing on top of a boulder. His hair begins to stand up, and Chrome gets the shock of his life when Senku reaches to touch him.

Kohaku and Ginro hold the ball and have their hairs stand up. Senku is unimpressed, and about to call out how primitive his science experiments were, but he stops halfway, realizing that Chrome is indeed primitive yet he discovered all the things he showed off, collecting and experimenting by himself with everything he kept in his storehouse.

Senku is then happy to see that even without any modern humans, there would always be people with the spark of curiosity that drove scientific discovery. He tells Chrome that this makes him one of the people Tsukasa would surely murder (though Chrome has no idea what he's going on about), and says that he'd love to have him and his resources for the kingdom of science. Chrome, finding himself cornered, challenges Senku to a last battle for the shed. Chrome's choice is the one skill no one has ever beat him at: arithmetic.

And thus, Chrome and his shed became part of the Kingdom of Science.

## Side Story: Chrome VS Senku Arithme-battle

Chrome gets ready to face Senku on a battle of numbers. He starts his offense with "8 x 8 = ?", shooting as an energy beam from his hands. This attack is deflected by both Senku and Kohaku, pointing out it's 64. Chrome is mortified by this, not expecting her to know any arithmetic. She elaborates that she's found a good use for multiplication, which is to estimate the quantity of a school of fish when fishing (which she apparently does by wielding her knives and body slamming the river).

Finding his first attack to be severely lacking strength, Chrome makes his next move, conjuring a massive energy ball he blasts Kohaku with: ''83 x 87 = ?''. The attack managed to defeat Kohaku and disintegrate her dress, ''How on earth could anyone know that?!'' she exclaimed in shock, but Senku, standing a few meters behind her, deflected it as well with a mere puff of breath answering 7221.

Chrome is growing desperate, as Senku sees through his strategy and explains that what Chrome is doing is using a quick solve method, which gives a fast answer to a two digit multiplication when the tens places are the same and the ones places add to 10. Multiplying the ones places gives the first two digits (3 x 7 = 21), and the tenths multiplied by its successor gives the next two digits (8 x 9 = 72).

Chrome is brought to his knees, but annoyed, Kinro steps in questioning the value of this whole display, as for his perspective, arithmetic is useless for battle. In an attempt to save face, Chrome argues that it could be used to analyze the power levels of fighters, with Kohaku adding that this could help balance team bouts.

She then goes on to assess the power levels of those present. Putting aside modesty, she scores herself with a power level of 1000, then come Kinro with 500, Ginro with 100, Chrome with 5, and Senku with 3. Senku accepted this estimation if the condition is not having his science to work with. Chrome complained about being so low, and so did Kinro, saying he was underestimated.

To settle this conundrum, she offers a sparring match. Chrome calls it an impossible game, while Ginro, definitely not out of cowardice, suggest they all team up against her and thus she wont have a chance.

Chrome calls his stance validated with Senku adding that indeed, 500 + 100 + 5 + 3 < 1000, as all four of them lay in a pile, heavily bruised while Kohaku triumphantly stands without a scratch.

## Characters in Order of Appearance

* Senku Ishigami
* Kohaku
* Ginro
* Kinro
* Chrome
* Tsukasa Shishio *(Mentioned)*

## Chapter Notes

* Ginro is scared of soap bubbles.
* Chrome makes his debut. A somewhat cocky teen who calls himself a sorcerer.
	+ Chrome discovered charcoal lye, the flame test, the sulfur ball generator and a multiplication quick-solve method by himself.
		- Senku is impressed with the discoveries he's made in the stone world with no knowledge of old world science.
	+ Chrome challenges Senku to a sorcery showdown just to show off. Later they put themselves at stake and Chrome loses.
	+ Chrome and his belongings become part of the Kingdom of Science.
* A new location, Chrome's shed is introduced, and becomes the new home base of the Kingom of Science.
* Kohaku fishes with swords and knows very basic arithmetic.
* Kohaku estimates the power levels of a few people:
	+ Herself: 1000
	+ Kinro: 500
	+ Ginro: 100
	+ Chrome: 5
	+ Senku: 3
		- Senku, Chrome, Ginro and Kinro try to fight her four on one, they get a beating out of it.

## Trivia

* The flame test involves introducing substances to a flame, causing a change of colour as this causes certain elements to emit light in their specific emission spectrum. Visually this causes different colours, but paired with a spectroscope, it was useful to identify specific substances and involved in the discovery of many chemical elements.
* The sulfur ball generator was invented by Otto von Guericke in 1663, it was the first electrostatic generator.
* Chrome's attacks during the arithme-battle visually resemble the Kamehameha and the Genki-dama from the Dragon Ball series.