Yes, there are quite a few. You can check out fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'Metal Sonic x Amy Rose' and you'll find a variety of stories, ranging from action - packed adventures to more emotional and character - driven ones.
Well, there are several. A prevalent theme is the clash of different natures. Metal Sonic's mechanical and often emotionless self against Amy Rose's passionate and emotional being. This can lead to themes of understanding and learning from one another. Another theme is the idea of an unlikely alliance. They might form an alliance against a greater threat in the Sonic world, and during this alliance, feelings start to develop. And sometimes, there are themes of sacrifice, where one of them might be willing to sacrifice for the other, which adds a lot of drama and depth to the fanfiction.
For Amy, she could become more understanding of the 'evil' or opposing side. Instead of just seeing Metal Sonic as a bad guy, she might learn to look deeper into his existence as a creation. This could make her more empathetic in general.
Even one of her friends like Tails could be the betrayer in a really unexpected plot twist. Maybe Tails is forced to betray her by some external threat. For example, if an enemy captures Tails and threatens to harm him or Sonic if he doesn't give away some important information about Amy Rose or lead her into a trap.
Well, the 'angel of darkness' is likely to be a main character. It might be an entity with its own motives and powers. Another character could be Sonic. He might play a role in trying to save Amy Rose from the influence of the 'angel of darkness' or be involved in some way in the events that unfold.
Amy Rose shows her love by constantly chasing Sonic. She is always by his side during his adventures, ready to help. For example, she'll bring him a meal or offer to patch up his wounds.
A 'amy rose dies fanfic' could be a very sad and dark take on the character. It might explore themes like loss, grief among the other characters who knew Amy Rose. Maybe it's a way for the writer to show how her death could impact the whole story's universe.
Amy Rose is a character full of charm. She is often seen as brave and determined. In one story, she set out on a journey to find a special flower that was said to have magical powers. Along the way, she met various friends and foes. She used her wits and kindness to overcome difficulties, and finally, she found the flower which she used to heal a sick friend in her village.
One common theme is redemption. Many fanfictions explore the idea of Metal Sonic being redeemed through his interactions with Amy. For example, Amy's kindness might make Metal Sonic question his evil programming.