The spells in Harry Potter could be combined with the Thu'um of the Dragonborn. For instance, a wizard could cast a spell to enhance the power of the Dragonborn's shout. Or the Dragonborn could use his shouts to disrupt spell - casting of dark wizards.
The magic systems could be combined by having the Dragonborn's shouts affect the magical creatures in the Harry Potter world differently. For example, his Animal Allegiance shout could make the Thestrals, Hippogriffs and other magical creatures in the Harry Potter world obey him. And wizards could use their spells to help the Dragonborn in battles against powerful dragons in the fanfic, like using Shield Charms to protect him while he uses his Thu'um to fight the dragons.
In a fanfic, the magic of the Dragonborn could be seen as an ancient form of magic in the Harry Potter universe. The Dragonborn's ability to absorb dragon souls could be related to the concept of Horcruxes in a way. Instead of splitting his soul, the Dragonborn absorbs the power of the dragon's soul, and this power could be used to counter the dark magic in the Harry Potter world. The Hogwarts professors could study the Dragonborn's magic to learn new ways to fight against Voldemort and his Death Eaters.
The magic in 'Harry Potter' is mainly based on spells, potions, and magical artifacts. In 'Devils and Realist', there are different types of powers related to demons and the political power plays. In a fanfic, one could combine them by having a spell that can summon or control a demon from 'Devils and Realist'. For example, a powerful wizard in the 'Harry Potter' world discovers an ancient spell that links to the demon realm in 'Devils and Realist' and starts to experiment with it, but quickly realizes the danger as the demons have their own motives and power hierarchies.
Well, in Narnia, there's the magic of Aslan which is more of a divine and nature - based magic. In Harry Potter, it's more about spells and potions. You could have a situation where a wizard tries to learn the magic of Aslan. For example, Hermione might be intrigued by the magic that brings Narnia to life and tries to study it. She could combine her knowledge of wizardry with the Narnian magic to create new spells.
The magic in Harry Potter is mainly spell - based, while in The Dragon Prince it is more about primal sources. In fanfiction, a character could try to combine the two. For instance, a wizard could use a spell to enhance the power of a primal source connection. They might use the Wingardium Leviosa spell to levitate an object charged with primal magic.
You could create a new type of magic that combines the two. Let's say there is a character in the fanfiction who is half - wizard from Harry Potter and half - something related to Black Butler (maybe has a demon ancestor). This character has a unique magic that is a blend of spell - casting and the ability to make deals with supernatural forces. Their spells might have a different effect because of the demonic influence. For instance, a simple levitation spell could also cause a small amount of fear in those around them because of the dark undertones from the Black Butler magic.
The magic systems could be combined in terms of magical education. Imagine a school where students from both universes learn. They would study the basics of both magic systems. So, a student would learn about the seven basic magecraft in Fate Stay Night as well as the different types of spells in Harry Potter. This would lead to a new generation of characters who could blend the two magics in creative ways. For example, using the teleportation magic from Fate Stay Night in combination with a Disillusionment Charm from Harry Potter for a stealthy escape.
In fanfiction, you could create a new magic system that combines elements. For Harry Potter, there's wand - based magic. In Percy Jackson, there's the power of the gods and demigod abilities. And in Guardians, there are all the high - tech gadgets and some alien powers. You could have a situation where a character uses a wand but channels the power of a Greek god through it, like using Zeus' lightning power through a wand spell. And the Guardians' tech could be enhanced by this combined magic, for example, a blaster that shoots out spells charged with demigod energy.
One way to combine Xenoblade 2 and Harry Potter in a fanfic could be to have the characters from Xenoblade 2 somehow end up in the wizarding world of Harry Potter. Maybe they could be mistaken for strange magical creatures at first. For example, the Titans in Xenoblade 2 could be seen as some sort of ancient, colossal magical beasts in the Harry Potter universe.
The magic in Harry Potter is based on spells, potions, and wands. The Mad Hatter's world has a more chaotic, Wonderland - like magic. In a fanfic, perhaps when the two magics meet, there could be unexpected reactions. For example, a spell from Harry's world cast near one of the Mad Hatter's magical hats might cause the hat to start singing and dancing uncontrollably. The wand - magic might interact with the Wonderland magic in a way that creates new, strange spells that neither world has seen before.
Magic spells from Harry Potter can be given Magic the Gathering - like mechanics. For example, the 'Expecto Patronum' spell could cost a certain amount of mana (like white mana for its purity aspect) and be used to protect against dark forces, which in the fanfiction could be related to certain types of Magic the Gathering creatures like demons.
In a fanfiction, the blending could occur in a more dangerous situation. Let's say there is a rift between the two worlds and the magic is getting mixed up in a chaotic way. The characters have to figure out how to control this new, combined magic. They might find that some spells from Harry Potter work differently when combined with the energy of the devils in Highschool DxD. For example, the Killing Curse might be affected by the demonic energy and instead of just killing, it could turn a target into a half - devil. This would force the characters to understand both magic systems deeply and find a way to separate or control the combined magic before it causes more harm.