Relationship building is also quite prevalent. It could be a friendship or a more complex bond between the male reader and the tentacle characters. There is also the theme of mystery, as the tentacle - related elements usually bring an air of the unknown. For example, in many stories, the origin of the tentacles or their purpose in the world is something the male reader has to figure out.
One common theme is discovery. The reader character often discovers the existence of tentacles in a new and unexpected world. Another theme is acceptance. They have to accept the presence and nature of these tentacles. For example, in some stories, the tentacles might be part of a strange but beautiful ecosystem.
A common theme is the exploration of the unknown. The tentacles often represent something strange and different from the reader's normal world, so it's about delving into that mystery. Another theme is connection, like how the reader forms a relationship, whether it be friendly or something more, with the tentacle - like entities.
Another common element is the relationship between the male reader and the tentacles. It could be a friendly one, where they help each other, or a more complex relationship where the male reader has to figure out how to coexist. Some fanfics play with the idea of the tentacles having a sort of sentience.
Love against all odds is a typical theme. In many male x male reader fanfiction, there are obstacles like family disapproval or social norms that the characters need to overcome to be together. Friendship is also often intertwined, as the relationship may start as a friendship and then develop into something more romantic.
A common theme is adventure. Since Frisk is often associated with an adventure - filled journey in the original game, this often gets carried over into the fanfiction. The male reader might join Frisk on his quest through the Underground.
One common theme is betrayal. Since it's about a cheater male, the sense of being betrayed by someone you love or trust is a big part of it. Another theme is heartbreak. The male reader usually experiences a great deal of emotional pain.
One common theme is friendship. Amaimon and the male reader might start as friends and have various adventures together.
A common theme is the journey of falling in love. The male reader often starts as a stranger or acquaintance to Yukino and then gradually they develop feelings for each other. Another theme is adventure. They might go on an adventure together, facing challenges and growing closer through those experiences.
One common theme is friendship. Often, the stories start with the male reader and Sasuke forming a bond as friends. They support each other through tough times. Another theme is growth. Both characters usually grow and change as a result of their relationship. For example, Sasuke may become more open - minded.
A theme that often shows up is mystery. Maybe there are secrets about Camilla that the male reader helps uncover, or they get involved in some sort of mystery together. Also, there can be themes related to power dynamics. Camilla might have certain powers or a high status, and how that affects her relationship with the male reader is explored in some fanfictions.