Another theme is defying family expectations. Often in these fanfictions, the characters' families have certain ideas about who they should be with. But the characters' love for each other is so strong that they are willing to go against their families' wishes and cross that limit to be together.
Breaking the barriers of physical disabilities is also a theme. In some fanfictions, a character with a disability falls in love with someone who sees past their limitations. It's about how love can be inclusive and powerful enough to make the physical differences not matter at all.
One common theme is the overcoming of cultural differences. For instance, two characters from different cultural backgrounds with different traditions and values come together in love. They have to navigate through misunderstandings and the pressure from their respective cultures, but love helps them break through these limits.
One common theme is unconditional love. No matter what the characters go through, their love remains steadfast.
One common theme is sacrifice. The characters are often willing to sacrifice a great deal for their love, showing that their love truly has no limits.
One common theme is the power of love to transcend the boundaries of life and death. In Twilight, the vampires are already sort of 'between' life and death, and when you add the concept of love beyond death, it becomes even more complex. Another theme could be sacrifice. A character might sacrifice their own 'undeath' or some other important aspect to be with their loved one who has passed on.
One great 'love beyond limits fanfiction' could be about a relationship that defies social classes. For example, a story where a poor artist falls in love with a wealthy heir. The characters have to overcome the prejudices and limitations set by society regarding their different economic backgrounds. It shows that love can be so strong that it goes beyond these worldly limits.
Another theme is self - discovery. Through her limitless love, she often discovers new aspects of herself. Maybe she realizes she is stronger and more capable than she thought when she is fighting for her love. For example, a woman might find out she has the courage to stand up to a powerful family member who is against her relationship.
One common theme is the exploration of different relationships. For example, fanfictions often re - examine the relationships between vampires and werewolves. Another theme is the expansion of the supernatural world, like introducing new types of magic or creatures.
One possible interesting plotline could be the exploration of a character who exists in the gray area between darkness and light. They might struggle with moral decisions that don't fit neatly into either category.
One common theme is friendship. Melanie might form a strong bond with Batman Beyond or other characters in the story. Another theme could be self - discovery. As Melanie enters this new and dangerous world, she has to figure out who she is and what she's capable of. For example, she could discover a hidden talent for combat or detective work.
I'm not sure specifically as it depends on the author's creation. But it could be characters who are on a journey to understand the true nature of darkness and light, like a young adventurer or a wise old sage.
Power is a common theme. The Dragon King's immense power and how he uses or controls it. Another theme could be isolation as he is 'beyond the wall'.