I think transformation is a key theme. The characters, especially the protagonist, are likely to go through a transformation. They start as perhaps an outsider coming into the villain's family, but over time, they become an integral part of it and may change the family's nature. There could also be a theme of mystery, as the villain's family is likely to have secrets that the protagonist uncovers during the story.
Well, love might be a theme too. It could be a love that defies the expectations of the 'villain' label. Maybe the protagonist falls in love with someone in the villain's family and this love challenges the pre - conceived notions about the family. Also, power struggles within the family could be a theme. With the villain's family, there are likely to be fights for power, inheritance, or control.
The protagonist is usually quite interesting. They are the ones thrust into the world of the villain's family and have to navigate through all the challenges. Their journey of adaptation and trying to fit into a family with a not - so - good reputation is captivating.
One of the main themes could be redemption. As the villain embraces the light, it often implies a journey towards redemption from their villainous ways. Another theme might be self - discovery. The villain is likely to learn more about themselves and their true nature through this process of embracing the good. Also, the contrast between good and evil is a key theme. It shows how the boundaries can be blurred when a villain starts to move towards the light.
One main theme could be redemption. The protagonist might be trying to change the fate of the villain's family, which implies a form of redemption for the family's actions. Another theme could be family dynamics. Despite being the 'villain's family', there are likely complex relationships within the family that the story explores.
In 'becoming the villians family novel', power and corruption could be important themes. The villain's family might be involved in power - seeking and corrupt practices, and the main character has to navigate through this. Also, identity is likely a theme as the character is changing their own identity by becoming part of this new family.
One interesting plot twist could be that the main character, who initially tries to resist becoming part of the villain's family, discovers that the villain has a noble reason for their actions. For example, the villain might be trying to protect a group of people from a greater evil that the outside world doesn't understand. Another twist could be that the family itself has a secret power that the main character unlocks, changing the power dynamic not only within the family but also in the world they inhabit. And perhaps the main character realizes that they are related to the villain in a way they never expected, which adds a whole new layer of complexity to their relationship and the story.
One possible plot twist could be that the siren, initially thought to be a tool for the villain, actually has a hidden agenda to redeem the villain's family. Another could be that the siren discovers she has a long - lost connection to the villain's family that changes the whole dynamic. And perhaps the siren's presence causes unexpected positive changes in the villain's family members, making them question their villainous ways.
Power struggle is likely a theme. As a villain, the character probably has to deal with other powerful entities, whether they are heroes or other villains, in a constant battle for power and influence. Also, identity might be a theme. The character has to grapple with being seen as a villain and how that affects their self - perception and relationships with others.
The siren might start as a mysterious and somewhat menacing figure. As she gets involved with the villain's family, she could gradually soften. For example, she may develop empathy through her interactions with family members. She could also learn new values from them and start to question her own motives.
The themes in this light novel are quite interesting. Self - improvement is a big one. The characters constantly strive to better themselves on their paths to godhood. Also, the theme of fate vs. free will exists. They have these thousand paths but are also bound by certain fates, and they need to figure out how to navigate that. And of course, there is the overarching theme of the pursuit of divinity, which drives the whole story forward.
One possible theme could be self - improvement. Since the goal is to become a god, the characters likely need to constantly grow and develop.