I recommend the two urban novels,"The Legendary Battle God's Husband" and "The Super City's Husband". Although he couldn't be sure which one was the specific novel mentioned, they all matched the plot where the male protagonist was an orphan adopted by the Lin family and had two sisters who were extremely powerful in martial arts. In these two novels, the male protagonist gradually rose through his struggles, displaying his wisdom and strength, and made his own way in the city. I hope you like my recommendation. Muah ~