One great korra x zuko fanfic is 'The Fire and the Water'. It beautifully weaves their different personalities and abilities together. The story takes place in a post - war world where they have to work together to rebuild. Another is 'A New Alliance' which focuses on their growing friendship that slowly turns into something more. It has really interesting dialogue that makes you feel like you're right there with them.
The contrast between their characters. Korra is brash and bold, while Zuko has a more complex and brooding personality. When these two are paired in a fanfic, it creates a lot of interesting dynamics. Their different bending abilities also add to the allure. Fire and water, which are opposing elements, can represent their relationship in many ways.
Zuko's complexity makes him so interesting in these fanfictions. He has a troubled past which has shaped him, but he is constantly evolving. His ability to show vulnerability in front of the reader is another great trait. It allows for a deeper emotional connection between him and the reader, as seen in stories where he opens up about his insecurities and fears.
The 'lemon' aspect might be a bit hard to come by in a clean way as it often involves inappropriate content. But for normal Korra and Mako fanfictions, you could also try FanFiction.net. Some stories there might show their relationship developing, their adventures together, and how they support each other, which can be really interesting to read.
Korra could meet the founders of the different bending disciplines. She could meet the first water benders and learn about the purest form of water bending. This would not only enhance her own skills but also give her a deeper connection to her water - bending heritage.
In 'Ozai Hurts Zuko' fanfictions, Zuko develops by facing his inner demons. The harm from Ozai makes him re - evaluate his life. He might become more empathetic towards others who have suffered, and this changes his outlook on the world. He also gains a new sense of self - identity, separate from what his father wanted him to be.
There's a possibility that Zuko would meet his grandfather. His grandfather's actions and decisions might have influenced the path the Fire Nation took towards war. By meeting him, Zuko could try to sway his grandfather's views and change the future of the Fire Nation at its root.
There could be a fanfiction where the kiss is a moment of impulse. Mako and Korra have been through a lot, and the emotions just build up until they can't hold it back anymore. This could then lead to a series of events where they have to deal with the consequences of this sudden display of affection, like how it affects their friendships with others in the group.