Another theme is sacrifice. The assassin may have to sacrifice their own happiness or safety for the sake of their love. They might be forced to choose between their love and their duty as an assassin. This creates a lot of internal conflict within the character.
Betrayal is a common theme. Since assassins often work in a world of secrecy and danger, there can be a lot of betrayal, either from their partners in the assassin world or from the ones they love. For example, in 'Mr. and Mrs. Smith', they initially feel betrayed when they find out each other's true jobs.
One common theme is the struggle between love and loyalty. The gangster and the assassin both have their own groups or causes they are loyal to, and their love challenges that. Another theme is redemption. They might see a chance to be better through their love for each other.
One common theme is the struggle between good and evil. The assassin may be initially seen as a dark figure but might have a moral code that challenges the traditional view. Another theme is identity. The assassin might be trying to figure out who they are within the context of the Twilight universe.
Friendship or camaraderie can be a common theme as well. Even though assassins are often solitary characters, in some fanfictions, they form alliances or friendships with other players. This helps them in their quests and also adds an emotional depth to the story. And of course, the overarching theme of survival is always there. They need to survive the challenges, enemies, and traps in the game world.
Well, a major theme is power. Merlin already has magic, which is a form of power, and as an assassin, he has another kind of power. How he uses these powers together or separately is often explored. Also, the theme of betrayal is common. As an assassin, he might be betrayed or he might have to betray others. And there's the theme of survival. In the dangerous world of being an assassin, Merlin has to find ways to survive. This could involve using his wits, his magic, or his assassin skills.
Power and control are also common themes. Harry as an assassin has a certain kind of power, and he has to learn how to control it. Also, the theme of identity crisis is often present. He struggles between being the Boy Who Lived and being an assassin. For example, in some fanfics, he questions if he's still the same Harry Potter or if the assassin role has changed him completely. And there's always the underlying theme of good vs evil, even though Harry is an assassin, he's usually fighting for the greater good in these fanfics.
One common theme is secrecy. Spies and assassins operate in the shadows, so their identities, motives, and methods are often hidden. Another theme is loyalty. They have to decide who to be loyal to, their employers, their countries, or their own moral codes. Also, there's the theme of survival. They are constantly in danger, so they need to use their skills to stay alive.
One common theme is the struggle with identity. Naruto, who is known for his bright and positive nature in the original series, has to come to terms with being an assassin, which is a much darker role. Another theme is secrecy. He has to keep his new identity hidden from his friends and loved ones.
One common theme is secrecy. The assassin often has to operate in the shadows, hiding their identity and true motives. Another theme is loyalty, as they might have to choose between different factions or individuals they could be loyal to within the combine world.
One major theme is morality. Fantasy assassin novels often explore the gray area between right and wrong. Is it okay to kill for a noble cause? Are assassins just tools or do they have their own agency? Another theme is loyalty. Assassins may have to choose between loyalty to their masters, their friends, or their own beliefs. Also, the theme of identity is common. Assassins may have to hide their true selves, or they may be searching for their true identity among the lies and disguises.