Level up Is Getting Me Undefeatable

After waking up in the body of the Young Master of the Luo family, he finds he has the knowledge of hundreds of games and Light Novels. However, he finds his Dantian is crippled, so he can't practice cultivation! Luckily, he has the Upgrade system. Killing Monsters, doing Quests, and even killing people- it's just too easy. I don't have any Martial Arts? I have hundreds of light novels, just let me level up so I can get this Main Character's Martial Art! The only problem is: Should I follow the "This OP character cultivation" or should I follow "Another OP character cultivation"?! The tragedy!