Another possibility is Marceline. She has her own dark side, just like the Ice Prince has his cold and aloof side. They could bond over their similarities. Marceline could also introduce the Ice Prince to different music and a more carefree lifestyle. They might start out as reluctant friends but grow to really care about each other as they go through various adventures together in the Land of Ooo.
A possible plot for an Adventure Time Ice Prince fanfiction might be that the Ice Prince decides to explore the warmer parts of Ooo. He's never been there before and is curious. But once he gets there, he realizes he can't control his ice powers well in the heat. He accidentally freezes some important things and has to make amends. Finn and Jake get involved to help him learn to control his powers in this new environment. It could also be a story about him learning about different cultures in the warmer regions.
One great example could be a fanfiction where Finn and the Ice Prince have to team up to save Ooo from a new, powerful enemy. In this story, Finn's bravery and the Ice Prince's ice powers complement each other in unexpected ways. They start off as reluctant allies but gradually develop a mutual respect as they face various challenges together.
They could also be portrayed as friends from different worlds who are trying to find common ground. The Ice Prince comes from a cold, isolated place, and Finn from a more adventurous and social world. A fanfiction could explore how they bridge this gap and create a unique bond that combines their different personalities and values.
In Adventure Time fanfiction, the Ice Princess could find allies in many characters. Lady Rainicorn could be one. Her flying abilities and combat skills could be very useful for the Ice Princess. BMO could also be an unexpected ally. BMO might have some knowledge or technology that could assist the Ice Princess in her adventure. Additionally, Flame Princess could be an ally under certain circumstances. If there is a threat that endangers both the Ice Kingdom and the Fire Kingdom, they could put aside their differences and work together.
In fanfiction about Ice King's daughter in Adventure Time, she often represents a new aspect of the complex Adventure Time universe. Her character can be used to explore themes of family, redemption, and the power of love. For example, some fanfictions might show how she helps Ice King regain his sanity or how she discovers her own identity in a world filled with magic and chaos.
The Lumpy Space Princess could also be paired with the Ice King. Her sassy attitude could contrast with the Ice King's craziness. In a fanfiction, they could end up on an adventure together where the Lumpy Space Princess tries to 'fix' the Ice King or just uses him for her own gain in a really comical way.
One interesting Ice Finn fanfiction could be about his adventures in a frozen realm that wasn't shown in the original series. Maybe he discovers a new type of ice creature and has to form an alliance with it to save the day.
I really liked 'Ice Finn's Frozen Quest'. It has Ice Finn going on a journey to find a magical ice crystal that can restore balance to the Ice Kingdom. It's full of action and some really cool descriptions of the icy landscapes.
One popular plotline is the Ice Queen's journey to find true friendship. In many fanfictions, she starts off as a lonely and misunderstood character. Another plotline could be her attempts to gain more power in the Land of Ooo, which often leads to conflicts with other characters like Finn and Jake. Some fanfictions also explore her past and how she became the Ice Queen in the first place.