One possible plotline could be Harry rising to power within the wizarding mafia world. He might start from a small - time operator and gradually build his empire. Another could be his conflicts with other powerful wizarding families who are also involved in mafia - like activities. He would have to use his magic and wits to outmaneuver them.
One possible plotline could be Harry taking over the wizarding underworld after defeating Voldemort. He might use his fame and the loyalty of his friends to start building his own 'empire'. He could control the trade of magical items and potions, similar to how a mob boss controls illegal trades. Another plotline could be Harry being born into a mob - like wizarding family instead of the Dursleys, and growing up learning the ways of the wizarding underworld from a young age.
One could imagine that a distant relative of the Black family, who has been disgraced or cast out, becomes a mafia boss. They still have some of the Black family's wealth and dark magic knowledge, but use it in a more criminal way. For example, they could be running a protection racket in Knockturn Alley, threatening shop owners to pay up or face dark magic. Severus Snape also could potentially be a mafia boss in an alternate story. He has the intelligence and the ability to be secretive. He could be using his potions expertise to create and sell illegal or dangerous potions on the black market, while also maintaining a network of spies and henchmen within Hogwarts and the wizarding world.
Power is a common theme. Harry, as a mafia boss, is often depicted as seeking and wielding power in different ways compared to the original series. Another theme is loyalty, as in the mafia world, loyalty to the boss and the group is crucial.
Well, in such a fanfiction, it could be that Harry Potter uses his magical skills in a more devious way like a mafia boss. He might use spells to intimidate or protect his 'territory' in the wizarding underworld. For example, he could use the Imperius Curse in a more mafia - like control way over other wizards to do his bidding.
One plot idea could be that the mafia boss is secretly protecting Hogwarts from a new dark threat. He uses his underworld connections to gather information that the Ministry of Magic can't access. For example, he might discover a group planning to steal powerful magical artifacts from the school. Another idea is that the mafia boss is actually a wizard who was exiled from the wizarding world long ago and has built his own criminal empire in the Muggle world. But when he hears about Voldemort's return, he decides to use his resources to help Harry Potter, in his own unorthodox way. A third idea could be that the mafia boss has a vendetta against a Death Eater who once wronged him in the past, and he teams up with Harry and his friends to take the Death Eater down.
One common plot could be power struggles. Harry Potter, as the mafia boss, might be constantly fighting other powerful wizards or groups who want to take over his 'territory' in the wizarding underworld. Another plot could be about revenge. Maybe someone from his past in the wizarding world wronged him, and now he's using his mafia - like power to get back at them.
One possible plotline could be about the Weasley family trying to improve their financial situation. Maybe they come up with a new business idea in the wizarding world, like a magical product that becomes a huge success and changes their economic status. Another could be a story about how the Ministry of Magic regulates the financial system in the wizarding world, and there are some characters who try to manipulate or reform it.
Well, one possible plotline could be a story where a character from the wizarding world, perhaps a powerful wizard, takes on a concubine in a parallel world or an alternate version of the wizarding society. The concubine might be from a different magical culture and their relationship could cause political or social unrest within the wizarding community.
One possible plotline could be that the parrot is a magical pet of a new character who enters Hogwarts. This parrot has the ability to detect dark magic, so it helps the students in their fight against the forces of Voldemort.
One possible plotline could be Harry being secretly trained by an unknown figure to become an assassin against the dark forces. He would have to hide this new identity from his friends at Hogwarts.