This Master Is Obviously Super Powerful but Too Cautious

"Master, you can cut mountains and seas with one sword, why do you have to pretend to be useless every day?" "Foolish disciple, if those things in the sky know the origin of your sword spirit... You and I will both die." Traveling through the world of cultivation, I was bound to a strange apprenticeship system—— Every time he cultivates Ling Shuang and breaks through a level, he can unlock a page of ancient secrets that have been erased by heaven. So I started to develop like crazy: Teaching her the "Nine Transformations of Sword Raising Technique" was actually to cover up the memory of killing gods sleeping in the sword soul. Taking her to the Northern Dark Abyss, the truth turned out to be the 120,000 Lord-devouring Swords that suppressed the abyss When the sword marks between her eyebrows reached the ninth level, the system finally showed its fangs—— "Congratulations to the host, the god-killing weapon training progress: 30%" Do you think I am raising an apprentice? No, I am raising a sword that can pierce the nine heavens!