The Master of Death status might make Harry Potter a target in the Warcraft fanfic. There could be dark forces in the Warcraft world that want to either use his power for their own evil purposes or simply eliminate him because they fear his influence. This could lead to a lot of action - packed storylines, with Harry having to fight off these threats while also trying to uphold his values from the Harry Potter world.
It could be that the character who is the Master of Death in the fanfic is seen as a prophesied figure in the Warcraft universe. Since the Master of Death has conquered death in the Harry Potter world, in Warcraft they might be seen as a being who can bring new life or restore balance. For example, they could use their power to heal the war - torn lands in Warcraft, much like how they might have used their power to protect or revive in the Harry Potter realm.
She could be a mentor figure. Just as Sherlock Holmes is known for his brilliant mind, Mummy Holmes could pass on some of that wisdom to the young wizards. For instance, she could teach them how to observe details more carefully, which is useful in both detective work and in dealing with the often - tricky magical situations at Hogwarts.
A 'creature baker' could be a source of unique magical treats. For example, they could make biscuits that give the eater the ability to communicate with certain magical creatures for a short time.
A father in a Harry Potter fanfic could also be an educator. He could teach his children about the wizarding world, its history, and magic spells. He might pass on family - specific magical knowledge that has been passed down through generations.
Well, Harry could find that his Deathly Hallows are perceived very differently in Asgard. His Invisibility Cloak might be seen as a powerful magical artifact like the ones in Asgard. His Resurrection Stone could be a source of great fascination as Asgardians have their own beliefs about the afterlife. And his Elder Wand might be seen as a weapon of great power, perhaps on par with Mjolnir.
He could be a purveyor of enchanted masks that give special abilities. For example, a mask that allows the wearer to speak Parseltongue even if they're not a Slytherin.
Perhaps Katrina Rinehart could be a seer. In the Harry Potter world, seers are very important as they can predict the future. If she were a seer, she could warn Harry and his friends about upcoming dangers, or she could be misinterpreted like Trelawney sometimes was. She would add an element of mystery and foresight to the story.
Death in Harry Potter fanfiction can also serve as a means of exploring the afterlife in the wizarding world. Writers might imagine different versions of what happens to a wizard's soul after death, whether it's a continuation of the journey in a different plane or a form of reincarnation within the magical realm. This adds a new dimension to the already rich world of Harry Potter.
Well, perhaps Harry Potter, as the master of death, could bring some of his magical knowledge to the DC universe. He might use magic to outwit the villains in DC. For example, he could use the invisibility cloak to sneak up on the Joker or use a spell to stop Lex Luthor's evil plans.
Perhaps an ancient spirit that has been awakened by the imbalance in the life - death cycle due to Harry becoming the Master of Death. This spirit sees Harry as the cause of the chaos and tries to destroy him to restore the balance in a way that is harmful to the wizarding world.