A possible plotline is that the older brother, having graduated from Hogwarts before Hermione, has a lot of connections in the wizarding world. When Hermione starts getting involved in the fight against the Dark Lord, he uses these connections to protect her. He might get her access to powerful protective spells or magical items that are not easily available. He could also be a bit of a maverick and not fully trust Dumbledore. So when Hermione is blindly following Dumbledore's orders, the brother steps in to make sure she's not being led into unnecessary danger. For instance, if Dumbledore sends Hermione on a dangerous mission, the brother might try to find an alternative way to achieve the same goal without putting her in harm's way.
Chapter 414, "The White Knife Goes In, The Red Knife Comes Out", is the clearest early answer because it turns Let's situation into a concrete plot event. It opens with Third Master really lives up to his reputation; his skills are...
Chapter 442, "Let's Form an Alliance", is the clearest early answer because a shaky connection becomes usable in the plot. The chapter turns that into something concrete by moving from Chang Rong was bewildered, "So, she seems pretty impressive." More...
Chapter 733, "Those People from the Jiang Family Are More Stupid than the Next!", is the clearest early answer because it turns Jiang Cheng's situation into a concrete plot event. The chapter gives readers a real answer by opening on Okay, Sister, you should go to sleep now.
Chapter 622, "Actually Tie Her Up?!", is the clearest early answer because it turns Gu Yu's situation into a concrete plot event. The chapter turns that into something concrete by moving from Watching the uncommon expression on the man's face, Su Yinwan was...
Chapter 434, "The Identity of the Feng Shui Master Can't Be Hidden Anymore", is the clearest early answer because the hidden truth stops feeling like mere subtext. The chapter turns that into something concrete by moving from He thought Jiang Li was just talking, but to his surprise, there...
Chapter 796, "No Such Person?!", is the clearest early answer because it turns Eve's situation into a concrete plot event. The chapter gives readers a real answer by opening on The lively family reunion night came to an abrupt halt, and the...
Chapter 584, "The Wealthy Young Master Renounces Worldly Life for Love", is the clearest early answer because it turns Seeing Jiang Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from There wasn't a mirror on the small boat.
Chapter 326, "Jiang Mingyu Stranded in a Foreign Land", is the clearest early answer because it turns South America's situation into a concrete plot event. The chapter turns that into something concrete by moving from And at this moment, on the other end of the Earth.
Chapter 648, "Even Wild Boars Make Way!", is the clearest early answer because it turns Pei Ye's situation into a concrete plot event.
Chapter 579, "I Know Where Team Q Is!", is the clearest early answer because it turns Su Yinwan's situation into a concrete plot event. The chapter turns that into something concrete by moving from Young Master, what do you think?" Having finished reading the... to Yet Jiang Li said, "Is that so?.