One more theme could be the exploration of the dragon's nature. Since the slayer is becoming part - dragon, they get to experience the dragon's instincts and characteristics from the inside. This can lead to a deeper understanding of the dragon species as a whole and how they are not just mindless beasts to be slain.
The theme of acceptance is also prevalent. The slayer has to deal with whether they can accept their new form and how others will accept them. There might also be a theme of redemption. If the slayer had a violent past towards dragons, their new form could be a chance for them to make amends.
One aspect to consider is the world - building in these fanfictions. How does a society react to a dragon slayer turned part - dragon? Are they feared, revered, or something in between? Additionally, the relationship between the slayer - turned - dragon and actual dragons could be explored. Do they now have an affinity with dragons? Or are they still at odds with them despite their new form?
A common theme is the battle between good and evil. The slayer is often seen as the hero fighting the 'evil' crystal dragons. Another theme is self - discovery. As the slayer faces different challenges, he often discovers new things about himself.
Power and growth are common themes. The slayer usually starts with a certain level of power and has to grow stronger. For example, in many fanfictions, they learn new techniques to defeat stronger enemies.
One common theme is family honor. The family often has a reputation to uphold as dragon slayers, and the characters strive to live up to that. Another theme is the power struggle. There might be competition among family members for who is the strongest or most skilled dragon slayer.
A common theme is power and its control. Sea Dragon Slayers often have to grapple with the immense power they possess. Another theme is friendship. They form strong bonds with other characters.
Another theme could be friendship. In the context of being a dragon slayer, Lucy's relationships with her friends, whether they are also slayers or just her regular comrades, are likely to be explored. Her friends might support her in her new role, or there could be some conflicts related to her new power. Usually, how these relationships evolve is an important part of the fanfiction.
Power and its consequences are also common. The water dragon slayer gains great power, but they also have to deal with the responsibility that comes with it. Sometimes, there are themes of sacrifice, where they have to give up something to save others or achieve their goals.
Well, a frequent theme is the discovery of new powers or abilities within Harry. Since dragon slaying is not part of his original Hogwarts curriculum, he has to figure out how to be effective. Also, the theme of friendship often plays a role. His friends may either support him or get involved in his dragon - slaying adventures. Additionally, there can be a theme of self - discovery as Harry finds out more about himself in this new and challenging role.
One common theme is power - up. Izuku gains the abilities of a dragon slayer, which makes him much stronger. Another theme is the exploration of a new identity. He has to figure out how to be both a hero - in - training and a dragon slayer.
One common theme is power - up. Naruto gets new abilities related to dragon slaying. Another could be friendship, like how Naruto's relationships change when he enters the dragon slayer world.