In the Nine Provinces, one's personal teacher was the most important in the world.
Regardless of occupations, even for a blacksmith, if the blacksmith's disciple made a major mistake, and the blacksmith killed them accidentally, the government wouldn't care about it. At most, the townspeople would gossip about the blacksmith.
A teacher had such great authority, but they naturally had to shoulder huge responsibility as well.
After a student took on a master. If the student ended up being useless trash in the end, their master/teacher would surely suffer a torrent of abuse.
Since the Tyrant Blade Yue Ba had accepted Yue Changdao as his disciple, he would naturally do his utmost to teach Yue Changdao.
Just like the saying 'a good teacher will produce a brilliant disciple', given that Yue Changdao's talent was extraordinary, as well as him having cultivated unceasingly during these ten years, he was exceptionally troublesome to deal with.