A possible plot could be that in a post - apocalyptic world where magic and Asgardian powers are the last hope, Harry and Thor are brought together by fate. As mates, they must find a way to combine their powers and knowledge. Harry's knowledge of magic and Thor's brute strength and godly powers could be combined in unique ways to defeat the chaos that has befallen their world.
Yes, there are quite a few out there. You can start by looking on fanfiction websites like Archive of Our Own or FanFiction.net. Just search for 'Harry is Thor mate' in their search bars and you'll likely find a variety of stories with different takes on how such an unlikely pairing could be mates.
One idea could be that Harry discovers a magical realm where Jareth rules and they initially clash due to their different personalities. But as they face common threats, like a dark force trying to invade both their worlds, they start to understand each other and form a bond. Another could be a story where Harry is transported to Jareth's world and has to learn the rules there to survive, and Jareth takes an interest in him because of his unique magic from the wizarding world.
A possible plot for Harry and Tom mate fanfiction is that they are both sent on a special mission by Dumbledore. Along the way, they have to rely on each other's strengths. Tom might use his intelligence and cunning, while Harry uses his courage and loyalty. They could also encounter magical creatures that they have to work together to defeat. This would force them to put aside their differences and form a bond. And as they complete the mission, they realize that they can learn a lot from each other.
In this fanfiction, Fem Harry might come from the wizarding world but be a reincarnation of an ancient goddess. Zeus, sensing her divinity, is drawn to her. Their relationship could be filled with power struggles as Harry is used to being independent and Zeus is used to being in control. It would make for an interesting dynamic as they try to understand each other's worlds and powers.
One idea could be a werewolf character finding their true mate among the Harry Potter characters. Maybe a werewolf who has always felt like an outcast in the wizarding world finally meets someone who accepts them completely. This could lead to a story of self - discovery and acceptance for both the werewolf and their mate.
One plot idea could be that Fenrir's mate is a powerful witch who has the ability to control his werewolf side. She could use her magic to soothe him during his transformations and together they try to find a way to end the discrimination against werewolves in the wizarding world. This would involve them facing many challenges, such as the Ministry of Magic's strict laws and the prejudice of other wizards.
A really interesting plot could be that a goblin mate has a unique magical ability that is the key to saving Hogwarts from a new dark threat. The wizarding characters initially doubt the goblin but gradually come to realize their importance and the power of their bond.
One plot idea could be Fem Harry struggling to come to terms with being Gabriel's mate. Maybe she's in a world where such a pairing is rare or frowned upon. Another could be them facing external threats together because their union is seen as a powerful force that some want to stop. For example, dark wizards or other supernatural beings might target them.
Jasper could be a time - traveler OC. She travels back in time and accidentally disrupts the timeline where she meets a young Harry Potter. At first, Harry is suspicious of her, but as they work together to fix the timeline, they form a bond. As mates, they have to deal with the consequences of their actions in the time - travel, such as preventing certain events from changing too much and also protecting their relationship from those who would oppose a time - traveler being involved with Harry Potter.
Another plot could involve her trying to fit into Asgardian society while still having her strong ties to the wizarding world. She might struggle with the different cultures and values. For instance, Asgardians might not understand her love for magic which is seen as a very different form of power in their world. She would have to find a way to bridge the gap between the two.