Then Uchiha Brahman came to the Underworld. He defeated a group of Asuras and taught them this new power. He taught everyone without discrimination: if you needed power, he would give it to you. In a short time, the Asuras who had learned the new chakra grew overconfident. They gave up their arduous ascetic practices and began cultivating chakra instead, opening their chakras to gain even greater power.
More importantly, once they reached the ultimate state and opened their final chakra, they would gain true immortality. Even if the world went through another cycle, they could awaken in the next one.
This was far better than that ascetic practice they had followed before. Asceticism could grant great power and all sorts of bizarre blessings, but it could never grant immortality. After their austerities, what many Asuras wanted most was to live forever and become invincible throughout the universe. Unfortunately, true immortality had already reached the limits of what this universe allowed. Aside from cultivation, there was no other way to attain it.
Even the Amrita only granted the gods immortality for this epoch. When the cycle ended, those destined to die would still die.
Perhaps the next epoch would give rise to an Emperor of Heaven, a Sun God, and a Moon God, but they would have nothing to do with the Emperor of Heaven and Sun God of this epoch.
They would be entirely new individuals.
As for cultivation, if it were so easy, the Asuras wouldn't have resorted to asceticism.
That meant cultivation was even more difficult than asceticism. It wasn't a system that could be mastered simply by relying on time, either. It was even harder than the cultivation system of immortals, since in that system, as long as one lived long enough, many realms could be