One possible magical property is that it can transform. It could turn into a different object when needed, such as a sword for combat or a shield for protection. It might also have the ability to store spells. Harry could load up the cane with spells in advance and then release them at a later time when he's in a difficult situation.
In some fanfictions, Harry Potter might own properties like his family's ancestral home, Grimmauld Place. It was originally Sirius Black's property but could be passed on to Harry as Sirius considered him family. Another property could be a magically enhanced cottage in the countryside where he could retreat and live a peaceful life away from the chaos of the wizarding world.
Perhaps it would have the power of enhanced spellcasting in water. Since many of his adventures involved water, like the Triwizard Tournament's second task, this would be useful. The wand might also have a connection to the Patronus charm, being able to emit a stronger Patronus without as much effort. This would be due to Harry's strong connection to his own Patronus and his need for protection. Also, it could have a self - repair function, which would be handy considering how often wands get damaged in battles.
It could be an ancient heirloom from a long - lost wizarding family. Maybe it was passed down through generations and finally found its way to Harry.
One possible scenario is that Harry discovers the Force during his time at Hogwarts. Maybe there's a hidden chamber or an old artifact that unlocks this power within him. Another scenario could be that he meets a character from a different universe who teaches him about the Force. For example, a rogue Jedi who has somehow ended up in the wizarding world.
One possible consequence could be his expulsion from Hogwarts. Using black magic is strictly prohibited in the wizarding world, and the school has a zero - tolerance policy. Another consequence might be the loss of his friends. His friends, who uphold the values of good magic, might not be able to accept his use of black magic.
One possible plotline could be an alternate universe where Harry is turned to the dark side early on. Maybe he discovers some false information about his parents' death and blames the wizarding world, leading him to use Avada Kedavra on those he believes are responsible.
In fanfiction, the Harry Potter language lozenges might have the effect of allowing the user to speak different magical languages fluently. For example, it could enable one to understand and communicate in Parseltongue without being a Parselmouth. This could lead to all sorts of interesting plot developments, like being able to decipher ancient spells written in a long - forgotten language.
He could lose the trust of his friends. In the original series, his friends rely on him to be a force for good. If he starts using the Dark Arts, they would be horrified and might distance themselves from him. Also, he could be in danger of being corrupted by the dark power, which could change his personality and make him more like the villains he once fought against.
In some fanfictions, Harry might use a flask to store potions. For example, he could carry a flask of Felix Felicis, the luck potion, with him during a dangerous mission at Hogwarts. This would give him an edge in tricky situations.
The sword might be a gift from a mysterious magical being. This being saw potential in Harry Potter and decided to give him the sword as a tool to help him in his future battles. It could have been enchanted specifically for Harry to face the unique challenges he will encounter.