Yes, Nawaki had spent only 1,000 Wish Power points to acquire the Asura Bloodline! This was the power of the Sage of Six Paths' own son, the pinnacle of Yang Release that symbolized the Sage's physical body and vitality!
What could 1,000 Wish Power points even do? Exchange for a kilogram of gold, or perhaps a kilogram of chakra testing paper?
Why could a mere 1,000 points exchange for a peak bloodline like Asura's? Was the noble bloodline inherited from the Sage of Six Paths really only worth a kilogram of gold?
Although the Wish Power System was incredibly miraculous and capable of performing all sorts of impossible feats, it was extremely costly, and its effects were nowhere near as exaggerated as that.
The reason Nawaki was able to obtain the Asura Bloodline for a mere 1,000 points was that his body already contained the bloodlines of both the Senju Clan and the Uzumaki Clan. Since these two clans were the only descendants of Asura and had always practiced intermarriage to ensure the purity of their bloodlines, it only cost 1,000 points to fuse and restore the two lineages.
To use an imperfect analogy, it is very difficult to conjure tomato and scrambled eggs out of thin air, but if you already have the tomatoes and the eggs, you only need to stir-fry them to get the dish.
Nawaki had checked the system: if he wanted to use himself as a template to exchange for the Asura Bloodline for an ordinary person without any bloodline, it would cost 200 million Wish Power points! The difference between the two was over a hundred thousand times; with his current measly 10 points of reputation, he wouldn't have enough even in 50,000 years! Furthermore, the perfect bloodlines of the Senju Clan and the Uzumaki Clan each required 100 million points.
The Wish Power System categorized Kekkei Genkai into four levels: Low, Medium, High, and Perfect, with exchange costs of 10,000, 100,000, 1,000,000, and 100,000,000 points respectively.
Take the Sharingan as an example: if Nawaki obtained the Uchiha Clan's bloodline template and exchanged it for himself, a Low-level bloodline would cost 10,000 points and could only unlock 1-tomoe; 100,000 points for Medium-level would unlock 2-tomoe, and so on. Unlocking the Mangekyo would require 100 million, and the Eternal Mangekyo would require 200 million!
Because Nawaki and Tsunade's grandfather was the head of the Senju Clan and their grandmother was a princess of the Uzumaki Clan, the bloodlines they inherited were both of the Perfect level, whereas the bloodlines of other branch members were much lower. It was only because the bloodlines within their bodies could not perfectly fuse—and even conflicted with one another—that their aptitude was affected, leaving their actual bloodline abilities equivalent only to High or Medium levels. Thus, Nawaki only needed to spend 1,000 points to perfectly fuse the Senju and Uzumaki lineages; otherwise, he would have had to wait until the end of time to exchange for the Asura Bloodline.
From this, it was clear that the Shinobi World was indeed a place where one's birth and bloodline determined everything; without a bloodline, one was destined to be cannon fodder for life.
As Nawaki's older sister, Tsunade possessed the same bloodline as him. If Nawaki were willing, he could exchange for the Asura Bloodline for her for just 1,000 points, but he chose not to.
Because using Wish Power to modify a bloodline took time and could not be achieved overnight, the person being modified could not be too far from the system during the process—ideally maintaining physical contact with Nawaki. It would also produce certain phenomena, and the person being modified would feel the changes within their body. If Nawaki exchanged the bloodline for Tsunade, she would definitely discover the secret of the system.
A one-year-old child performing such an incredible miracle could not be explained by the word "genius"; he would only be seen as a freak or a monster. Such unknowns would bring fear to others, leading to disgust and exclusion, much like how Naruto was called a "demon fox" by the villagers because of the Nine-Tails' power.
Even if Tsunade might suppress her fear and doubt out of sisterly love and keep his secret, Nawaki was unwilling to take the risk. Human hearts could not withstand such tests, and only a fool would test their own family.
There was another important reason: if Tsunade acquired the Asura Bloodline, her talent would surely lead to rapid, explosive growth in strength. As a major character in the Shinobi World, this would trigger a series of major changes! For instance, if Tsunade's strength far surpassed Jiraiya and Orochimaru, would they still form a team? If they couldn't continue to team up, would the title of Sannin even emerge, and would the fates of Jiraiya and Orochimaru change?
After gaining the powerful physical strength and vitality of Asura, would Tsunade still focus on medical ninjutsu, and would the Konoha Medical Corps even be established?
Upon discovering that Tsunade possessed a massive amount of chakra capable of suppressing the Nine-Tails, would Konoha simply have her replace Kushina as the Nine-Tails Jinchuriki?
After such a series of changes, the subsequent development of the entire Shinobi World would shift drastically. As a transmigrator, Nawaki's greatest advantage—his knowledge of the plot—would cease to exist, and the future would become uncontrollable.
Therefore, Nawaki decided not to exchange the Asura Bloodline for Tsunade for the time being. At the very least, he would wait until he was twelve and had safely survived the fated death-trap of the Second Shinobi World War before considering it again.
Although Nawaki's bloodline had undergone an atavistic transformation after perfectly fusing the two clans, granting him the Asura Bloodline and a very powerful body and chakra, he lacked a Tailed Beast. Thus, despite his potential, he could not ascend to powerful strength in a single step.
In the original work, Asura was quite weak in his early stages and only gained strength after long-term training, barely managing to contend with Indra. It was not until the Sage of Six Paths extracted the Ten-Tails from his body, turned it into the nine Tailed Beasts, and sealed the Nine-Tails within Asura that he could truly fight to a draw with the Eternal Mangekyo-wielding Indra, eventually perishing together.
As for the later generations, the Nine-Tails Jinchuriki and Child of Prophecy, Naruto, also did not have high strength in his early stages. It was only after learning the Rasenshuriken and using Nine-Tails chakra to rival the speed of the Flying Thunder God that he possessed Kage-level strength. In the later stages, he was like a cheater, receiving help from the Sage of Six Paths and combining Sage Art chakra with Nine-Tails chakra to surpass Kage-level and reach Six Paths-level. Finally, together with Sasuke—who possessed Indra's chakra and had also received the Sage of Six Paths' gift of the Six-Tomoe Rinnegan—they defeated Kaguya Otsutsuki.
Although Naruto's strength reached its peak at the end and was equal to, or even slightly stronger than, Sasuke's, Naruto had been suppressed by Sasuke's strength throughout the journey.
And why were the two rivals who also possessed Asura and Indra chakra, Hashirama Senju and Uchiha Madara, evenly matched from beginning to end, ultimately perishing together? That was because Hashirama Senju possessed the Wood Release Kekkei Genkai!
Therefore, the Asura Bloodline was weak in the early stages and explosive in the late stages, whereas the Sharingan remained strong from start to finish. If one wanted to ensure a combat advantage in the early stages, one had to acquire the Wood Release Kekkei Genkai.
However, to cope with the great catastrophe at age twelve, Nawaki needed to increase his strength rapidly; he had no time to train and accumulate power slowly. His best path to rapid growth was to obtain his grandfather's template and then exchange for the Wood Release Kekkei Genkai.