In some fanfictions, they might show Harry having dark powers through things like unexpected magical outbursts with a malevolent tinge. For example, he could accidentally use a spell that causes harm in a way that seems to draw on darker magic. However, in the original series, Harry is firmly on the side of light magic, so this is a departure in fanfiction.
Often, in these fanfictions, the discovery of a new, ancient and dark magic artifact can be a plot device. Harry might find this artifact and, as he tries to understand or control it, he starts to develop dark powers. Also, the idea of a prophecy misinterpreted can play a role. A prophecy that was thought to be about his heroism is actually about his fall to the dark side, leading him to explore and use dark powers.
The powers might also change the way magic is perceived in the story. If Harry can do things like read minds or foresee events, it could make other forms of magic seem less powerful in comparison. Or it could inspire other characters to explore different, more psychic - related magic, thus expanding the magical lore in the fanfiction.
Well, if Harry Potter has Deadpool's powers, he might become more carefree and irreverent. His traditional sense of duty could be tempered with Deadpool's chaotic nature. He could start cracking more jokes during dangerous situations, like when facing Voldemort. His attitude towards rules might change too, as Deadpool is not one to follow rules strictly.
Well, there are fanfictions where Harry has godlike powers such as the ability to resurrect the dead. This completely changes the dynamic of the wizarding world as it goes against the natural laws of magic in the original series. Another aspect could be his mind - having the power to read and control the thoughts of every living being, making him almost omniscient and omnipotent within that fictional world.
One challenge could be controlling his new powers. Deadpool's powers are quite wild, and Harry, used to more traditional magic, might struggle to master them. Another challenge could be how the wizarding world views him. His new powers and the resulting change in his behavior might make him an outcast among some in the wizarding community.
Well, if Harry Potter had sans powers, he might be able to teleport around Hogwarts easily. This would make it much simpler for him to avoid danger or get to his classes on time. For example, when facing Voldemort, he could suddenly disappear and reappear behind him to gain an advantage in battle.
One cool power often seen in such fanfiction is teleportation. This allows characters to quickly move from one place to another, escaping danger or arriving at crucial moments just in time. There are also powers related to healing, where a character has an extraordinary ability to cure any injury or illness, which can be very useful in the often - dangerous wizarding world.
Harry might gain the ability to dodge attacks more easily. Sans has a certain 'instinct' for avoiding harm, and if Harry had this, it would be much harder for his enemies to land a hit on him. This would be really useful in duels, especially against powerful dark wizards. It could also make his Quidditch playing even more amazing as he could dodge bludgers effortlessly.
Harry's magic is mainly based on incantations and the use of a wand. Sakura's magic, especially as Dark Sakura, is more instinctual and connected to her very being. Their powers could interact in a way that Harry's spells could act as a sort of catalyst for Sakura's power. For example, if Harry casts a spell of protection around them, it could enhance Sakura's ability to focus her dark magic without it going out of control.