It might be a tale of mystery and discovery, with the cloak leading the boy to hidden places or secrets in the wizarding world.
Perhaps it's a story of friendship and bravery, where the boy and his cloak face various enemies together and grow stronger through their experiences.
The cloak could change his life by making him more confident. If he's able to use it to his advantage, like sneaking into places he normally couldn't, he might gain a sense of power. For example, he could overhear important conversations that give him an edge in his studies or in dealing with bullies at Hogwarts.
Perhaps the cloak is a family heirloom that the boy only discovers when he's in a time of great need. It could be a cloak that was enchanted by an ancestor with a specific purpose, like protecting the wearer from a particular dark magic. As he starts using the cloak, he realizes that it comes with a set of rules and responsibilities. He has to figure out how to use it to his advantage while also fulfilling whatever the cloak's original purpose was. This could lead to him learning more about his family's past and his own place in the wizarding world.
Maybe Ron is jealous of Harry and wants to have something that belongs to him for a change. The cloak gives Harry a certain freedom and mystery, and Ron might be longing for that kind of experience.
It could be a dark and tragic fanfic where the boy has to make a difficult choice that leads to sacrificing Harry Potter for a greater cause.
I'm not sure specifically as there could be many different 'Cloak of Courage Fanfic' out there. It could be about a magical cloak that bestows courage on the character who wears it and their adventures while having this cloak.
Since the term 'lemon' often implies something inappropriate in fanfic context, we could instead think about how a proper fanfic about Harry and his mother might focus on her love for him, like how her sacrifice protected him. This could be developed into a story about the lingering influence of her love on Harry's life at Hogwarts.
It could be that the character's development doesn't match the original or expected traits. Maybe they act out of character or the story takes an unexpected turn with this aspect.
It might make his friends a bit wary at first. Since this is an unusual and powerful thing to happen, they could be concerned about how it's changing Harry. But as they see that Harry is still the same person deep down, they would gradually accept it.
One possible fanfic could be about Remus Lupin's search for a permanent cure to his lycanthropy. It might involve him traveling to far - off places, meeting with ancient healers or magic users who claim to have the knowledge. Maybe he teams up with some of his old Hogwarts friends like Sirius or James in flashbacks, and they try to find a cure together. This would add an element of friendship and adventure to the story.
One idea could be that when Harry absorbs the cloak, he gains the ability to become truly invisible, not just to the eye but also to magical detection spells. This could lead to him sneaking into places like the Ministry of Magic undetected and uncovering secrets about Voldemort's past plans.