"Thank you very much," Kai expressed his gratitude to Marigold.
Marigold waved her hand dismissively. "You're welcome. Armament Haki is relatively rare in other places, but it's quite common in the New World. Even if I hadn't taught you, you could have learned it from someone else in the future."
"Whether we learn it here or from others, we should always be grateful to those who teach us."
"Well, since you taught us how to use Haki, I'll teach you something in return as a way of repaying your kindness."
"What are you going to teach? Is it ninjutsu?"
The women of the Nine Snakes gathered around curiously. They had all witnessed the power of ninjutsu and were naturally eager to learn such abilities.
"The reason ninjutsu isn't commonly taught is not due to unwillingness, but because it requires Chakra to perform. It's like how a Devil Fruit's ability cannot be taught to others."
"What I can teach you is breathing—the Breath of the Snake."
"Breath of the Snake?"
"The breathing technique, as the name suggests, is a method of breathing. Continuous practice of this technique can subtly improve physical fitness. When using breathing methods, your physical capabilities can be greatly enhanced."
"When you completely replace ordinary breathing with this technique, your body can naturally maintain this posture at all times."
The expressions of everyone in the Nine Snakes crew grew serious. They were not fools; they quickly grasped the significance of what Kai was saying. The idea that breathing could make one stronger was a revelation. This secret method was something they had never heard of before, and if it spread, it would cause a massive sensation.
"Are you telling the truth?" Hancock asked, looking at Kai solemnly.
"Whether it's true or not, you'll find out if you try it yourself."
Kai met Hancock's gaze, his eyes shifting into a Sharingan pattern. Hancock felt herself enter a trance, and suddenly she found herself standing in a forest. Everyone else had vanished, leaving only Kai standing across from her.
"Don't panic; this is an illusion. I'm here to teach you the Breath of the Snake, along with the corresponding sword skills."
In the outside world, only a few seconds had passed. Hancock regained her senses and glanced around. The scene appeared unchanged, as if only a moment had elapsed.
"What's wrong, sister?" Gong Denghua was the first to notice something was off and quickly asked her sister.
Hancock waved her hand dismissively. "It's okay. I've learned the Breath of the Snake. I'll teach it to you later. Gong Denghua, you teach them Observation Haki. I'm a bit tired, so I'm going to rest now."
After Hancock finished speaking, she turned and walked toward the cabin.
The other members of the Nine Snakes were surprised by Hancock's words. Since Master She Ji said so, the breathing technique must be effective.
That meant their strength could improve after learning it.
The women of Amazon Lily viewed strength as a form of beauty, and those who became members of the Nine Snakes had already stood out among thousands on the entire island. The desire to become stronger was stronger among these women than among many men.
Initially, they had kept their distance from Kai and the others, as they understood men better than the women on the island. But now, they were becoming increasingly enthusiastic toward Kai and his companions.
Hancock returned to her room, collapsed onto the bed, and pressed her right hand against her chest. She felt her heart racing.
Here's the revised version of your text with "Xuan Yan" replaced by "Kai," along with grammatical corrections and adjustments for an American English style:
"What's wrong with me?"
Is this because of practicing the breathing techniques? Why do I keep thinking of that annoying Kai's face lately, and why does my heartbeat quicken whenever I think of him?
"Oops! Here we go again!"
No, I can't think about that guy anymore. I need to focus on practicing that breathing method first.
Hancock took a deep breath, calming herself, and began to practice the breathing techniques seriously.
Kai was also surprised by Hancock's talent. She truly had the aura of a queen. It took her only an hour to learn the breathing method in the illusion space. Her aptitude was just slightly lower than that of Shisui and Itachi.
Meanwhile, Gong Denghua began teaching Kai and the others Observation Haki.
Observation Haki sharpens one's five senses and allows the user to detect the breath and emotional changes of nearby creatures. It can be used to predict and avoid danger.
Observation Haki has multiple functions, including sensing attacks, predicting an opponent's next moves, gauging the strength of creatures, sensing their emotions and thoughts, and determining the location and number of objects outside one's field of view.
A powerful practitioner of Observation Haki can even foresee the future.
However, using Observation Haki is closely tied to one's mental state. You need to remain calm to ensure its effectiveness; it cannot be used when you are emotional or losing your composure.
Just like before, Kai quickly mastered Observation Haki. In the 'transparent world' state, he had ultimate control over every part of his body. The sharpness of his five senses allowed him to easily perceive everything around him.
He could sense the number and location of everyone in the Nine Snakes crew, the birds soaring in the sky, and the fish swimming in the sea. It was a strange feeling, as if everything was under his control.
Gong Denghua explained, "Observation Haki is different from Armament Haki. Observation Haki is the power of perception. Even if you have talent, it requires diligent training and understanding; it cannot be mastered overnight..."
"Thank you, I've learned it," Kai replied confidently.