Some common themes could be friendship. Despite their differences, Sonic as the Werehog and Shadow might develop an understanding and a bond. Another theme could be adventure. They could team up to face a common enemy or explore a new and dangerous area.
They might combine their powers through a sort of energy transfer. Shadow could transfer some of his chaos energy into Sonic while he's in Werehog form, enhancing Sonic's already formidable abilities. This could also work the other way around, with Sonic sharing his Werehog - specific energy with Shadow to give him new skills or boost his existing ones.
One common theme is friendship. Many fanfics explore how Sonic and Shadow can overcome their differences and become friends or at least allies. Another is the concept of redemption, especially for Shadow who has a complex past.
Often, there is a theme of power and its control. The Werehog form gives Tails new powers, and in many fanfictions, he has to learn how to master them without causing harm. For example, in some stories, he might accidentally cause destruction while still getting used to his enhanced strength. It's also about his journey to use these powers for the right reasons.
Another theme is the idea of acceptance. Sonic may struggle with his werehog form at times, and Amy's acceptance of him in that state can be a central part of the story. It shows how love and friendship can transcend physical appearances and differences, and how they support each other through difficult times.
One common theme is self - discovery. The werehog often has to figure out his place in the Sonic Boom world and what his powers really mean. Another theme is friendship, like how the werehog interacts with Sonic and other characters in the series.
A common theme is self - discovery. The Werehog often has to figure out his place in Sonic's world. Another theme is the struggle between the two forms, Sonic and Werehog.
One common theme is the struggle between good and evil. The werehog, often representing the more wild and instinctual side of Sonic, and the vampire, usually a symbol of the dark and mysterious, are pitted against each other. Another theme is identity. Sonic has to deal with his dual nature as a werehog while facing the vampire threat.
One common theme is the idea of friendship evolving from rivalry. Sonic and Shadow start as foes but in many fanfics, they gradually become friends or at least respect each other more. For example, in 'Sonic and Shadow: A New Understanding', they learn about each other's motives and start to see the good in one another.
Adventure is also a big theme. The baby versions of Sonic and Shadow often go on exciting quests. They might be looking for a lost item, exploring a mysterious place, or trying to defeat a villain, which makes for really engaging stories.
There might be a fanfiction where the Werehog Sonic and Shadow are thrown into an alternate dimension. In this dimension, they have to face different versions of themselves and their friends. Their relationship evolves as they fight side by side, with Shadow being initially skeptical of Sonic's Werehog abilities but eventually coming to respect them.