Amy is another character that shows up a lot. Writers might explore her relationship with Sonic more deeply, like how she supports him during the rebuilding process or if she has any new dreams or goals in the post - adventure world.
Sonic himself is usually really popular. Whether it's the Sonic from Sonic X or Sonic Underground, he's the main hero and often at the center of the action. People love reading about his adventures and how he deals with the challenges in the combined universes.
Classic Sonic and Modern Sonic are the stars, of course. However, Knuckles can also be a very popular character in these fanfictions. His role as the guardian of the Master Emerald in the classic world and his continued importance in the modern Sonic universe make him an interesting addition. He can be the one who initially doubts the partnership between the two Sonics but then comes around. And Amy Rose is another character that often appears. Her feelings for Sonic, both Classic and Modern, can add a touch of romance or at least some emotional depth to the story.
Edward and Bella remain popular as they are the central characters of the original Twilight series. Their relationship is often further explored in the aftermath scenarios.
One interesting concept could be exploring the emotional aftermath for the characters. For example, how Sonic deals with the consequences of his adventures on a deeper, more personal level. Maybe he has nightmares about the battles he's been in.
Sonic's son is often a very popular character. He usually inherits Sonic's speed and has his own unique personality.
Well, Shadow is a really popular character to include. His dark past and his similarities and differences with Sonic can create a lot of interesting storylines. Rouge the Bat is also a great choice. Her thieving ways and her complex relationships with other characters can bring a different flavor to the fanfiction. And don't forget about Dr. Eggman. He's the main villain in Sonic X, and his wacky inventions and evil plans are essential for creating conflict in the story.
The main characters are probably Sonic and an alternate version of Sonic. There could also be other Sonic characters like Tails or Knuckles making appearances to support the Sonics in their rescue mission. But Sonic and his doppelganger would be at the forefront, using their speed and skills to achieve the rescue.
There could also be some new characters introduced in this fanfiction. Maybe a mysterious figure who has the power to control Dark Sonic or someone who has a connection to the origin of Dark Sonic. These new characters can bring fresh plot twists and new relationships to the story.
Sonic himself is always popular. His speed and heroic nature are central to many fanfics. Then there's Sally. She is often a key character, especially in stories that involve strategy and leadership. Bunnie is also well - liked. Her mechanical enhancements can add an interesting element to the story. And of course, Antoine, with his comical French accent and sometimes clumsy but brave nature, makes for great character interactions in the fanfic world.
Sonic himself is of course a very popular character in abdl sonic fanfiction. His speed and adventurous nature can be interestingly combined with the abdl concept. Tails also often appears as he is Sonic's close friend. He can play a role in helping Sonic deal with the situation if Sonic is in an abdl state.