Although Yamato had the ability of Wood Release, the power of his Wood Release was weaker than Hashirama's. It lacked power and decisiveness in battle. It was not enough to fight a ninja of the same level. Yamato's Wood Release was not as practical as his Earth and Water release.
Therefore, after putting him under a genjutsu, Ryoha had also realized this, so he just let Yamato use his Earth Release. This kind of genjutsu was completely in line with the inner thoughts of the opponent. It was really effective since people always follow their inner thoughts. The person affected by this jutsu would think they are just following their own thoughts, so it was hard for them to escape from this particular genjutsu.
Therefore, although Yamato's Wood Release might look strong, that was really not the case. If he did not have Wood Release, his position in Konoha would not be so high. After all, he was the only successful experimental subject in Orochimaru's research on Wood Release.
Ryoha was not interested in fusing Yamato's genes. He wanted to obtain the Wood Release genes that were at the same level of mastery as his Sharingan. After dissolving the 3-tomoe Sharingan, he would obtain its complete genes and mix them into his body, allowing his body to devour the genes of the Sharingan.
As he continued to evolve, he obtained the abilities of the Sharingan. Ryoha had his own genes devour the Sharingan genes, not the other way around. Therefore, with the help of Bulma's technology, Ryoha was able to reach 100% compatibility with this ability of the Sharingan.
In the case of other Uchiha clansmen, except for the development of the Sharingan to the Eternal Mangekyo, their control over the Sharingan was slowly suppressed by the Sharingan itself. However, Ryoha was different. In the beginning, not only was his status higher than the Sharingan, but he was also the master of the Sharingan, completely controlling everything about the Sharingan.
He would not let the Sharingan enslave him. The Sharingan was his slave. No matter how powerful the Sharingan was, it was nothing without his control.
The reason why Ryoha took away Yamato's blood was to let Bulma study the genes contained in his blood. This kind of gene was be obtained from the cells of the First Hokage. Its strength was diluted and weakened over the years.
Wouldn't it be easier for Wood Release genes, which had weakened so much, to be fused with the genes drawn from his own blood? Of course, he had no knowledge of this field of expertise. Gene studies were too complicated. It was better to let Bulma do the work.
When Ryoha took Yamato's blood, he was doing it on a whim to teach a lesson to someone who dared to spy on him. He did not know whether the blood would be useful for Bulma's research. Even if it was not, it would not be a loss.
After properly preserving the blood in his hands, Ryoha continued on his way. However, this time, he used the Body Flicker jutsu to travel. He was more secretive this time, as he didn't want to be followed anymore. It was better to go home quickly.
"Eh? You're back, Ryoha." As soon as he opened the door, he heard Bulma's voice. It could be said that as long as one came within 10 meters from Bulma's house, she would immediately know who it was because there were all kinds of mini-detectors around, which could monitor everything in this big house.
This is how Bulma played around with the surveillance of Konoha these past years, so that she could hide from all the spying so she wouldn't be discovered by Konoha, which would risk their lives.
"Bulma, I brought you some good stuff. Last time, because the First Hokage's body was tightly monitored by a lot of people, If any part of it was missing, they would immediately find out, and then it would be troublesome. So I could only bring back a small amount of blood that has been preserved for many years without any change, but this time I brought this."
"This person's blood contains the cells of the First Hokage. You should be a little bit careful with them, though, since the First Hokage's cells was very powerful."
"The cells of the First Hokage were extensively studied. Some have tried to fuse them with genes in order to obtain the enormous chakra and abilities it possesses.
"This blood was from the only person that survived those experiments. Moreover, he can also use the Wood Release. However, the power of his Wood Release was too weak. Its offensive power was weaker than the usual Fire Release and even the Water Release.
Ryoha greeted Haku, who stood beside Bulma, and then handed over the kunai that was covered in Yamato's blood to Bulma.
He also found that Haku, who never smiled and gave people a very sad feeling, was smiling brightly at him after he returned from the Chuunin Exam. That smile was pure and beautiful.
It seemed that Bulma had enlightened Haku and taken her out from the shadow of her childhood. She was no longer a tool but a person.
Ryoha was happy and relieved for Haku. He was much stronger than when he was in the Land of Waves.
She was a woman who could use chakra. She was strong and had great potential. The most important thing was that Ryoha knew the real character of Haku. He was absolutely assured that she would protect Bulma. And with her there, maybe she could help Bulma's experiment with her chakra when he was not around. The careful and serious Haku was obviously a big help to Bulma.
"You came at the right time. The blood sample you brought before was, well, whatever. It was ruined now." Bulma said, a little embarrassed.
"What? Destroyed?" Ryoha widened his eyes and looked at Bulma in disbelief. All these years, he had never seen Bulma ruin her samples. Once Bulma was involved in the research, she would show the temperament of a strong woman and a leader. She was very attractive.
With that dashing self-confidence and never-give-up mindset she had, Ryoha believed that nothing was difficult for Bulma. As long as she put her mind to it, she could invent anything. Now, he actually heard that she did not fail but destroyed the sample. How could he not be surprised?