Return to the Heart of the Sword

In 2248 AD, Cheng Feng used the soul traveling device invented by his old friend Luo Ye to travel back to the past, trying to change the ending of his lover's death because he was not strong enough. Although Cheng Feng's soul successfully returned to the past, he completely forgot all the memories. He only knew that he should work hard to become stronger. How should he change his mistakes in the future after returning so that his lover can survive in this world...