A common theme is the struggle for acceptance. Bella often has to accept the new situation of Paul's imprint on her. Another theme is the change in relationships. Her relationships with other characters, like the Cullens or her human friends, may shift due to this new bond.
One common theme is the struggle with the unexpected. Paul suddenly imprinting on Bella is a huge shock, and many fanfictions explore his internal conflict as he tries to come to terms with this new feeling.
One popular 'bella phases and imprints on paul fanfiction' is 'Bella's New Path'. It explores Bella's different emotional phases and how they impact her relationship with Paul. Another good one could be 'The Imprint's Influence' which delves deep into how Paul's imprint on Bella changes their lives and the pack dynamics.
One common theme is self - discovery. As Bella phases into a wolf, she has to learn about her new self, her powers, and her place in the supernatural world.
A major theme is growth. Both Paul and Seth grow as individuals and as a pair. They learn about themselves and each other. Also, the theme of loyalty often comes up. Their loyalty to each other and to the pack has to be re - evaluated and adjusted because of the imprint. For example, in some fanfics, they have to prove their loyalty to the pack while still maintaining their new bond.
One common theme is the exploration of a non - traditional relationship. Since it goes against the normal pairings in the Twilight series, it often delves into how society within the story (the vampire and human world) reacts to it. Another theme is self - discovery for both Bella and Rosalie. As their relationship forms, they learn more about themselves and their place in the world around them.
Conflict is also common. There could be conflict between the vampire and werewolf factions due to Bella's imprinting. Or there might be internal conflict within Bella herself as she tries to come to terms with the sudden and powerful imprinting bond that has changed her life so drastically.
One common theme is the idea of an unbreakable bond. Since imprinting is such a strong concept in the Twilight world, fanfictions often explore how this bond between Seth and Bella is unshakable, no matter what challenges they face.
There could be a dark magic user. This person might be jealous of Bella's relationship with Paul or wants to use her for some dark magic ritual. So they put Bella in danger, and Paul phases to protect her. The dark magic user would then be the main antagonist in this fanfiction.
One of the main themes to avoid is the inappropriate and non - consensual nature of the 'imprinting on a baby' idea. It goes against basic moral and ethical standards regarding relationships.
One common theme is family. Since Bella imprints on Esme and Alice, it often explores how this new connection affects the family dynamic within the Cullen family.