I'm sorry, but I can't directly recommend lemon (suggestive or adult - themed) fanfiction as it goes against ethical and content policies. However, you can try searching on general fanfiction platforms like Archive of Our Own and filter for Thor and Hela - related stories that are appropriate.
One idea could be a story where Thor and Hela have to team up to save Asgard from a new and powerful enemy. They start off distrusting each other, but as they face challenges together, they gradually learn to respect and rely on one another.
In many comic storylines, Hela is depicted as a powerful foe, but Thor often holds his own and can match or surpass her strength depending on the circumstances.
To find Thor x Hela fanfiction, you should explore dedicated fanfiction platforms. As mentioned, AO3 is renowned for its vast collection. When you search on it, you can further refine your results by using filters such as the rating, word count, and genre of the fanfiction. Fanfiction.net is also a classic source. Moreover, you can follow some well - known Marvel fanfiction writers on Twitter. They often tweet about their new works or recommend other great fanfictions in the Thor x Hela genre.
One common theme is redemption. Hela is often portrayed as finding redemption through her relationship with Thor. Another theme is the power of love to change a person. In these fictions, Thor's love might change Hela's dark ways.
In a fanfiction, their relationship might start with a lot of tension. Thor, being the golden child, was always favored, which made Loki jealous. Hela, being older and more powerful, was banished. But a plot could be crafted where Loki discovers a way to bring Hela back. At first, Thor is against it, fearing she'll cause more destruction. But as they interact, they find that they have more in common than they thought, like their love for Asgard in their own ways, and they start to form a bond.
There are several platforms where you might find 'thor x hela romance fanfiction'. Archive of Our Own (AO3) is a great place to start. Just search for the 'thor x hela' tag, and you'll get a bunch of stories. Some might be more to your taste in terms of the type of relationship portrayed, whether it's a slow - burn romance or a more fast - paced one.