Well, it works by mixing the two distinct universes' elements. For instance, the magic from Harry Potter and the extreme combat scenarios from Doom. The fanfic writers might give Harry Potter the ability to use Doom - like weapons or give Doomguy some magical powers. It creates a really unique and exciting blend.
The unique storylines also come from the fact that the two universes have different power systems. In Harry Potter, it's about magic power and knowledge. In Riddick, it's about physical strength, combat skills, and the ability to survive in harsh conditions. Fanfiction can explore how these power systems interact. Maybe a character from Riddick's world is given a magical item and has to figure out how to use it without any prior knowledge of magic, or a Harry Potter character has to rely on Riddick - style survival skills when their magic fails them.
In Harry Potter fanfiction, blacksmithing often involves a combination of magic and traditional metal - working skills. The blacksmith may use spells to heat the metal to the right temperature or to shape it in ways that normal tools couldn't. For example, they might use a 'Flamingus' spell to create a strong, even heat for forging.
In certain fanfictions, Harry Potter's shapeshifting ability could be a result of a special spell or potion he discovers. It might work like a charm that he has to cast on himself, and the more he practices, the better he gets at it. For instance, he could find an ancient spell book that reveals the secrets of shapeshifting, and from there, he starts to experiment with different forms and how to control the transformation process.
Another way the 'Harry Potter is summoned' concept works is when a magical being with great power summons him. This could be a powerful wizard from another land or a magical creature like a phoenix or a centaur. They might summon Harry because they sense his unique magic or because they believe he has the ability to solve a problem that they can't. For example, a centaur might summon Harry to help deal with a dark magic that is corrupting the forest it guards.
Time change in Harry Potter fanfiction can be a really interesting concept. There are fanfictions where time is like a malleable thing that can be bent to the will of the characters. Some stories might have a young wizard or witch accidentally stumbling upon a time - altering power. This could lead to them going back in time and interacting with the founders of Hogwarts. They might learn new magic from them, which then changes the way they deal with the present - day threats in the wizarding world. It also might cause confusion as they try to fit this new knowledge into the existing magical framework.
In Harry Potter fanfiction, creature inheritance often varies. Sometimes it can be a hidden trait passed down through families. For example, a character might inherit werewolf genes from a distant relative. It could also be related to magical abilities that are specific to certain magical creatures, like the ability to communicate with snakes if there's some sort of serpent - related inheritance. Usually, it adds an extra layer of mystery and power to the characters in the fanfiction.
In some fanfictions, time travel works through special magical artifacts. For example, the Time - Turner is often used in more elaborate ways than in the original books. It might be able to send a person not just back a few hours, but years or even centuries. In other stories, certain powerful spells can open up time - travel portals. These spells are usually very difficult to master and often have dangerous side - effects if not cast correctly.
In some fanfiction, gravity magic works by the wizard's will and concentration. They can visualize the change in gravitational force and direct it towards a specific object or area. For example, if they want to make an object float, they focus on reducing the gravitational pull on that object.
In some Harry Potter fanfiction where there is control over werewolves, it often involves powerful magic. For example, the use of spells like the Imperius Curse might be a way to control werewolves in a non - traditional sense. However, this is a dark form of magic and is usually frowned upon in the wizarding world.
It might work through powerful time - turning spells. These spells could be created by ancient wizards and passed down. The chamber could have a set of rules, like only those with pure intentions can enter and manipulate time within it.