One common theme is redemption. Megamind is often portrayed as seeking redemption for his past actions. Another theme is friendship. Fans like to write about how Metro Man and Megamind become friends despite their differences.
Fast male novels usually referred to youth school novels, in which the protagonists were mostly young singers who experienced the gap between their musical dreams and reality. In the process of pursuing their musical dreams, they experienced many setbacks and tribulations. The theme of a fast-man novel was usually about youth, love, friendship, music, and so on.
It's hard to say exactly. It likely involved a lot of creativity and inspiration from the author. They might have drawn on their own experiences or observations of urban life.
Another great place to find Metro Man and Megamind fanfiction is Archive of Our Own. It has a wide range of stories with different themes. Some might be humorous, like a story where they accidentally switch powers. Others could be more serious, exploring the psychological aspects of their characters in new situations.
The war in Metro 2033 started due to a global nuclear conflict. Different countries' tensions and power struggles led to the ultimate unleashing of nuclear weapons.
You usually need to follow the in-game instructions for account transfer in City Story Metro. It might involve linking to an external account or using specific settings within the game.