In Assassin's Creed Black Flag, Desmond's story is intertwined with the modern - day search for First Civilization artifacts. He accesses the memories of his ancestor, Edward Kenway, through the Animus. His journey is about uncovering secrets that could have a major impact on the present - day world and the struggle between the Assassins and Templars.
One interesting fanfiction could be where Desmond has more in - depth interactions with Ezio. Maybe it shows how Ezio's skills and experiences influence Desmond in unexpected ways. For example, Desmond might learn some of Ezio's more subtle assassination techniques through a dream - like connection.
The book that ended Desmond's story, like 'Assassin's Creed: Revelations', is significant as it ties up loose ends. It shows how Desmond's actions and experiences throughout the series have led to a certain point. It also provides more context about the Assassin - Templar struggle from his perspective. His story in the book is a culmination of all the knowledge and power he has gained over the course of the previous stories. It also sets the stage for possible future developments in the Assassin's Creed world, even if his own story has come to an end.
One interesting concept could be a crossover with a fantasy world like Middle - earth. Imagine an assassin having to navigate the perils of Mordor while still maintaining their creed. Another concept might be a crossover with a historical event not directly related to the main Assassin's Creed timeline, such as the sinking of the Titanic, where assassins could be on board for a secret mission.
The theme of redemption through the connection with ancestors is also common. Maybe Desmond has made some mistakes in his own life, and by exploring the memories of his more noble ancestors like Ezio, he finds a path to redeem himself. It's a deep and engaging theme that often shows up in fanfiction.
Writing a good Assassins Creed crossover fanfic is all about balance. You have to balance the elements of Assassin's Creed, like the hidden blade and the assassin's parkour skills, with the elements of the crossover. Let's say it's a crossover with a detective story. You can't overshadow the detective's investigation skills with the assassin's combat abilities. Also, create believable relationships between the characters. If an assassin teams up with a detective, there should be some initial mistrust that gradually turns into respect and cooperation as they work towards a common goal.
Desmond Doss was a remarkable man. He was a conscientious objector during World War II. He refused to carry a weapon but still served as a medic in the military. He was deeply religious and his beliefs guided his actions, which were truly heroic on the battlefield as he saved many lives without using violence himself.