Since this is an improper concept for the Harry Potter world, there are no so - called 'good' plotlines in such fanfic. We should uphold the positive values that J.K. Rowling intended in the original work, rather than exploring such unseemly fan - created ideas.
Well, perhaps in 'the king harry potter fanfic', there's a plotline where Harry discovers a long - lost magical artifact that gives him the power and status of a king. This could lead to him having to face off against old enemies who now see him as an even greater threat. And his friends from Hogwarts might have to band together to protect him as he adjusts to this new role. Also, it could involve new magical creatures being drawn to him because of his new - found king - like aura.
Well, one interesting plotline is when fanfics explore Carrow's relationship with the other Death Eaters. Some show him as being in a power struggle, which adds a whole new layer of drama.
Perhaps in the fanfic, Harry is turned into a snake for a period of time. As a snake, he experiences the wizarding world from a different perspective. He has to learn how to survive as a snake while still trying to fulfill his role in the fight against Voldemort. He might encounter other snakes that are either friendly or hostile, and he has to use his wits to deal with them.
A great plotline in some fanfics is the discovery of new spells and magic. It could be that a long - lost spellbook is found, and the characters start to experiment with spells that are more powerful and dangerous than what they are used to. This could lead to all sorts of situations, from accidentally creating new magical disasters to using these spells to fight off new, unexpected enemies.
Well, one plotline could be the main character, perhaps a new healer at Hogwarts, dealing with magical maladies that are beyond the usual. For example, they might encounter a spell - induced illness that spreads among the students and has to find a unique cure using both traditional and forgotten healing methods.
One interesting plotline could be Voldemort being redeemed. It's a really different take as in the original books he's pure evil. But in fanfic, some writers explore what if he had a change of heart.
One possible plotline could be that Harry has unique magical abilities due to being raised by Death. Maybe he can communicate with the dead more easily and gain knowledge from them that gives him an edge in the wizarding world.
Well, perhaps in this fanfic, Harry being the son of a dragon gives him some unique magical powers. He might be able to breathe a special kind of fire that can counter dark magic. And there could be a plotline where he has to prove himself to both the wizarding community and the dragon community. He could be caught in the middle of a conflict between the two, trying to find his place and use his powers for good.
One interesting plotline could be about the rebuilding of Hogwarts. The war has left it in ruins, and the characters have to come together to restore it to its former glory. They might face challenges like finding the right magical materials and dealing with the memories of the battles that took place there.
One interesting plotline could be the discovery of a long - lost inheritance in Gringotts that has a powerful magical object. Maybe it's a wand with special abilities that can only be unlocked by a specific heir. This could lead to a race between different wizarding families to claim it.