In a fanfiction, Sona's brother could be a mentor figure. He might teach Sona some ancient and powerful magic that has been passed down in their family. He could also be a bit of a rebel, going against the traditional ways of the devil society. For instance, he might believe in more equal relationships between devils and other races, like angels or humans, which could cause some conflict within their family and among the other devils.
One possibility could be that Sona's brother is a powerful figure in the underworld. He might be involved in political intrigue within the devil society. For example, he could be trying to form alliances with other noble devil families to increase the power and influence of Sona's family. Maybe he has some special abilities that are yet to be discovered by others, which he uses to his advantage in the complex power dynamics of the Highschool DxD world.
Perhaps Sona's brother has a tragic past. He could have lost someone he loved dearly in a war between devils and angels. This event could have shaped his personality and goals. He might be on a quest for revenge or trying to find a way to prevent such tragedies from happening again. His relationship with Sona could be complex, as he wants to protect her from the same pain he has endured, but also knows she needs to grow strong in the dangerous world they live in.
A practical answer is Chapter 142, because it turns the idea into a concrete scene. The chapter opens with The ingredients for making Buddha Jumps Over the Wall were still on their..., adds pressure through The unique taste and aroma almost blew his eyebrows away., and ends on Wen Jiaojiao.
Look to Chapter 129 for the clearest answer. It begins with When they saw that the live chat was full of praise for Jiang Li, those..., keeps building through Had they been used as pawns by publicity accounts?!, and lands on With that thought, he smugly turned on his phone..
The best chapter pointer here is Chapter 150, "Has She Been Cursed?!". It opens with Upon hearing the first part of Jiang Li's words, Zhang Cheng dismissed... and closes on He spent the last few days visiting various renowned doctors, while also....
Look to Chapter 193 for the clearest answer. It begins with Jiang Shixu's eyes lit up when he heard there was a gift., keeps building through But the next second, he carefully asked, "Is this gift for everyone?" "No,..., and lands on Jiang Cheng was a prime example..
If you want the clearest chapter reference, go to Chapter 180. Early on, In the end, everyone received gifts that were completely opposite to what...; later, the chapter leans on Shu Yan wanted plastic films, but she ended up with a box of facial masks..
Look to Chapter 134 for the clearest answer. It begins with After a brief noon rest, the production team was up to their antics again., keeps building through Just as several guests had finished their relaxing hot showers and were..., and lands on [Are you kidding me, is Jiang Li putting on an act.
A practical answer is Chapter 131, because it turns the idea into a concrete scene. The chapter opens with Just around mealtime, Director Sun came over pushing his small food cart., adds pressure through Just as they tried to emulate Jiang Li's example and make themselves a..., and ends on Hungry.
The best chapter pointer here is Chapter 114, "I've never seen someone so shameless!". It opens with As time passed, the number of viewers in the live broadcast gradually... and closes on But just now, an uncle came and said not to give you anything to eat." Qi....
Look to Chapter 177 for the clearest answer. It begins with I'm actually the last?!" After the scores were announced, Wen Jiaojiao's..., keeps building through She slapped the table in disbelief., and lands on It was with great difficulty that she had gained a wave of fans in the....
A practical answer is Chapter 172, because it turns the idea into a concrete scene. The chapter opens with Not only Shu Yan, but the entire internet was shocked when they saw Su..., adds pressure through It seems Director Sun kept it quite tight-lipped., and ends on Where's the chaotic scene I was.