One possible plotline could be that Sonic fails to save Chris from a dangerous situation in time, causing Chris to break down crying. For example, if a powerful enemy captures Chris and Sonic has to fight through many obstacles to reach him. Another could be that Chris feels left out as Sonic spends more time with his other friends, leading to his crying and Sonic having to make it up to him. Maybe Sonic gets so caught up in his adventures that he forgets an important event for Chris, like his birthday.
It could be that Chris's family is in some sort of trouble, like they are about to lose their home. Sonic tries to help but things seem to be getting worse, and Chris cries out of desperation. Also, Chris might be bullied at school for being friends with Sonic. When Sonic finds out, he has to deal with the bullies and console the crying Chris.
In a fanfiction scenario, Tails might cry when he discovers that his past actions have had negative consequences on the Sonic X world. He's always been so eager to help, but if he realizes he accidentally caused harm, it could break his heart. Another situation could be that there's a natural disaster in the world they live in, and Tails is unable to save some of the small animals he loves so much, leading to his tears. And there could be a time when Tails is excluded from a group activity by mistake, and his feelings of being left out make him cry.
To best portray the emotional aspect, the author should focus on the build - up to Chris's crying. Maybe show the small disappointments or fears that Chris has been suppressing over time. When he finally breaks down, it will seem more natural. Also, the reactions of other characters around Chris, apart from Sonic, can add depth. If his family members are also sad or concerned, it can amplify the emotional impact of Chris's crying.
One common theme is friendship. Since Sonic and Chris are from different worlds in the Sonic X series, their growing friendship is often explored in fanfictions. For example, how they learn to understand and support each other.
One possible plotline could be that Chris gets infected and Wesker tries to control or use him for his own evil plans. Another could be that they both get infected in different ways and have to find a cure together while dealing with their changing bodies and relationship.
One possible plotline could be that Sonic is facing a new and extremely powerful villain who manages to outwit him in a battle and ultimately kill him. This could lead to his friends, like Tails and Knuckles, vowing revenge and setting out on a journey to become stronger to face the villain.
One popular Sonic x Chris sister fanfiction might involve them going on adventures together in Sonic's world. They could face various villains and solve mysteries side by side. It might also explore their relationship development, like how they gradually become closer friends.
One common plot could be Sonic trying to rescue Chris from the kidnappers. Sonic's super speed would be a huge advantage in tracking down the kidnappers' location quickly. He might use his Sonic Spin Dash to break through any barriers in his way.
A lot of the fanfiction might revolve around the idea of teamwork. They have different skills and abilities, and when they work together, they can overcome various challenges. Also, the theme of discovery can be present, as they might discover new places or powers in the stories.
Well, it could be a story about them teaming up for a project. Maybe they collaborate on a video series and face various challenges along the way, both in terms of content creation and dealing with the public reaction.
Themes in these fanfictions can vary widely. But some of the most common ones include loyalty. They might face situations where their loyalty to each other is tested. Another is the theme of sacrifice. There could be stories where one of them has to sacrifice something for the greater good of the group. And the theme of acceptance is also there, with them learning to accept each other's flaws and strengths.