I'm not sure who Aku specifically is. Aku could be a person with a great imagination who tells all kinds of stories, like adventure stories, fairy tales or even true - life stories.
It could be someone from the Naruto universe who doesn't like Naruto's newfound fascination with Aku. For example, Danzo might see Naruto's interest in Aku as a threat to the stability of the village and try to stop Naruto from further exploring Aku - related things. So, Danzo could be the main antagonist in this case.
The character of Aku could be developed in a 'pregnant Aku in Samurai Jack fanfiction' by exploring how he interacts with the world around him differently. He may become more reclusive as he doesn't want others to see his 'weak' state. Or he could become more aggressive in trying to protect his pregnancy, which would be a new aspect of his character. Also, his relationship with his own power might change. Maybe he has to find new ways to use his magic that don't harm the unborn, which would force him to grow and adapt in ways he hasn't before.
One idea could be a crossover where Aku accidentally opens a portal to the Naruto universe. Naruto, being the curious and brave ninja he is, decides to explore Aku's world. They could start off as enemies, but gradually come to understand each other's motives and end up teaming up against a greater evil that threatens both of their worlds.
Some quotes about love from novels could be 'Love is patient, love is kind' from religious texts which are often quoted in novels with a spiritual or moral undertone. Another might be from 'Pride and Prejudice' where Mr. Darcy says 'I have been a selfish being all my life, in practice, though not in principle'. This shows his journey in love and self - discovery.
Take the character Heathcliff from 'Wuthering Heights'. His quotes about his love for Catherine are full of passion and a sense of possession. His statements like 'I cannot live without my life! I cannot live without my soul!' show how his love defines him and makes him a complex and tortured character. These quotes not only show his love but also his extreme personality.
Another theme is perseverance. The lovers usually face numerous obstacles, such as misunderstandings, family opposition, or social constraints. But they keep on fighting for their relationship, which shows great perseverance. For example, in many such novels, the couple might be from different social classes, and society looks down on their relationship. But they still strive to be together.