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.
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.
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.
First, you need to understand the characters well. Sonic in his Werehog form has different abilities and a somewhat different personality compared to his normal self. Shadow also has his own complex character traits. Try to incorporate these into the story. For example, Sonic's Werehog strength could be used in a fight scene against a common enemy.
One popular theme is adventure. Writers often send Sonic the Werehog and Amy on exciting adventures together, facing various challenges and enemies. Another theme is romance, of course, as it's about their relationship. There's also the theme of self - discovery, where either Sonic or Amy discovers something new about themselves during their time together in the story.
A 'Metal Sonic x Shadow Fanfic' might explore an interesting dynamic between the two characters. It could involve their unique abilities interacting in different scenarios. For example, Metal Sonic's robotic precision and speed combined with Shadow's chaos powers could lead to some really intense action scenes. Also, the fanfic might delve into their personalities, perhaps showing a rivalry or an unexpected alliance.
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.
Well, another place could be some Sonic - dedicated fan forums. There are often fans sharing their own written fanfics there. Sometimes, they might even recommend some really great 'sonic the werehog x amy fanfic' that they've come across. It's a good way to discover new and interesting stories within the Sonic fandom.
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.
You can try fanfiction.net. It has a large collection of fanfics including those related to sonic werehog. Just search for'sonic werehog' in the search bar and you'll get a list of relevant stories.