In 'Akame ga Kill', Tatsumi and Esdeath's relationship is complex. Esdeath falls deeply in love with Tatsumi. However, Tatsumi is on the side opposing Esdeath's cruel ways. Esdeath's love is intense but possessive. She tries to make Tatsumi hers, but Tatsumi is committed to his comrades and the revolution. Their love story is tragic as they are on opposite sides of a great conflict.
Tatsumi doesn't really welcome Esdeath's love. He sees her as an enemy due to her actions in the empire. Her brutal ways and her role in oppressing the people are things Tatsumi is fighting against, so he can't return her feelings of love.
One common theme is the idea of redemption. Often, the OC tries to bring out a softer side of Esdeath, as if redeeming her from her cruel ways. Another theme is the power dynamic. Since Esdeath is a powerful character, the relationship with the OC often explores how power affects their interactions.
For Tatsumi, start with his initial impression in the school. Maybe he's a bit naive at first. As he interacts with Akame more, he could become more confident and assertive. Akame, on the other hand, might start as cold and distant. But as she spends time with Tatsumi, she begins to open up. You can show this through their conversations. For example, Tatsumi might make a joke and Akame might start to smile more often around him.
Esdeath's character can be developed by exploring her backstory in relation to the thief. Maybe she had a similar experience in her past where she was an outcast like the thief. This can make her more empathetic towards the thief. The thief's character can be developed by showing their growth from being a simple thief to someone who has a greater purpose, perhaps influenced by Esdeath's grand plans. As they interact, both characters can change and adapt, making their relationship more complex and interesting.
One plot idea could be that the thief is initially stealing from Esdeath's domain. Esdeath catches the thief but is intrigued by their skills and instead of punishing them, forces the thief to work for her. As they spend time together, an unlikely bond forms between the cold - hearted Esdeath and the wily thief.
Well, a great plot could be a school competition. Tatsumi and Akame are on different teams at first, but as the competition progresses, they find themselves drawn to each other. They start to secretly help each other out, which is against the rules. This causes a stir among the other students and teachers. And in the end, they might decide to forfeit the competition to be together, showing that their relationship is more important than winning.
Tatsumi is very likely to be involved as he has a significant relationship with Esdeath in the original story. Her subordinates in the Jaegers might also be part of the fanfic. They could be shown as being protective or having mixed feelings about her pregnancy.
One popular 'Esdeath x OC fanfiction' is 'A Frozen Heart's Thaw'. It delves into the relationship between Esdeath and an original character in a unique way. The OC in this story has a backstory that intertwines with Esdeath's cold nature, gradually melting her heart through a series of adventures and emotional exchanges. Another great one could be 'Esdeath and the Unlikely Ally'. Here, the OC is a character with a different ideology than Esdeath at first, but as the story progresses, they form an unexpected bond.