Yes, there are some interesting 'Harry is Stannis' fanfictions out there. You can start by looking on popular fanfiction websites like Archive of Our Own. Some works might explore how Harry's personality traits from his own story could blend with the characteristics of Stannis from his respective lore.
One great Stannis fanfic is 'The Siege of Dragonstone'. It really delves into Stannis's strategic mind during a crucial event. Another is 'Stannis and the Red Priestess', which explores his relationship with Melisandre in a very interesting way. And 'Stannis's Redemption' shows a different side of him, as if he's on a path to reclaim his honor in a more complex world than what's shown in the original work.
In fanfiction, the relationship between Stannis Baratheon and Sansa can be quite complex. Some fanfictions might explore a political alliance between them. Stannis, being a rather stern and duty - bound character, could see Sansa as a valuable asset in his quest for the Iron Throne. Sansa, on the other hand, might initially be cautious but could gradually come to respect Stannis' sense of justice.
A possible fanfiction could focus on Melisandre's mysterious powers in a new light. Maybe she uses her magic to grow a lemon tree in the harsh winter of Westeros. This could symbolize hope in a desolate time. The lemon could then be used in some sort of ritual or offering, perhaps to one of the many gods in the Game of Thrones universe.
One common theme is the exploration of her powers. Many fanfics focus on how she uses her magic in different situations. Another theme is her relationship with other characters, like how she interacts with Jon Snow or Davos Seaworth.
Lady Melisandre is a red priestess from Asshai. She believes in the Lord of Light. She came to Westeros to support Stannis Baratheon, believing him to be the prophesied Azor Ahai reborn. She has the power to create shadow assassins and uses her magic and influence to further Stannis' claim to the Iron Throne.
In this fan fiction, their relationship may develop in a complex way. Stannis may initially use Jon as a tool to gain more support in the North, seeing his Stark name as an advantage. But as Jon shows his true self and his unique skills, Stannis starts to value him for who he is. Jon, on the other hand, may be initially hesitant about serving Stannis but gradually realizes that he can learn a great deal from him. Their relationship could be full of power struggles, but also moments of mutual admiration and growth.
These fanfics could potentially bring out the contrast between Stannis' stern and duty - bound personality and Lyanna's more free - spirited and perhaps headstrong nature. They might create a story where they have to overcome differences in their beliefs and family loyalties. For example, Stannis is all about following the rules and doing what's right for the realm, while Lyanna might have her own ideas about honor and freedom. The fanfic could show how they navigate these differences while falling in love.
One great 'Game of Thrones Stannis Fanfiction' is 'The Red King'. It delves deep into Stannis's complex character, exploring his unwavering belief in his right to the Iron Throne. The author does an excellent job of portraying his inner turmoil and his struggle with the harsh realities of Westeros politics.