Perhaps fem Harry has visions that are related to Loki's past or future. This could cause her to seek him out. As they meet, they start to understand each other better. Loki, being the trickster, might initially be skeptical of her seer abilities but as time goes on and her visions prove accurate, they form an unlikely alliance. They could then be on a journey to either change Loki's fate or prevent some great disaster that Harry has seen in her visions. This could involve battles against other magical or mythological beings.
A common theme is the clash and subsequent harmony of their different powers. Fem Harry's seer powers and Loki's magic often start in conflict but end up complementing each other. Another theme is the exploration of their relationship, whether it's a romantic or a more platonic partnership based on mutual respect and the need to survive in the story's universe.
Another option is to follow some fanfiction authors who are known for writing in the Harry Potter and Loki crossover genre. You can look for their works on various platforms. Some authors might have written something along the lines of fem harry being a seer for loki. Check out the reviews and ratings of their works to see if it's something that might interest you.
One popular fem Harry x Loki seer fanfiction is 'The Seer's Path'. In this story, fem Harry has the gift of seeing the future which ties her to Loki in unexpected ways. Their relationship develops as they face various challenges together in the magical world.
The theme of identity is also quite prevalent. The seer has to figure out who she is in the context of all the supernatural beings around her. Is she just a seer? Or does she have a greater purpose? This exploration of identity often drives the character's development in Vampire Diaries OC Seer fanfiction. It's like she's constantly trying to find her place in this crazy world of vampires, witches, and werewolves.
Another theme is self - discovery. The OC, who is often an outsider or someone with a unique background, also goes through a journey of self - discovery while interacting with Loki. They both learn about themselves and their capabilities through their relationship.
There's this 'Loki x OC Fanfiction' called 'Love in the Shadows'. The OC in this story is a thief with a heart of gold. She accidentally steals from Loki and that's how their story begins. It's full of witty banter between them. The author has created a really unique OC who is not intimidated by Loki's power and status, which makes for a very engaging read.
Well, there's 'A Seer's Awakening'. In this fanfiction, the OC seer discovers her powers gradually and gets involved in the complex relationships of the Vampire Diaries characters. It has some great character development and the author does an excellent job of making the seer's powers seem both mysterious and believable. It also adds a new dimension to the already rich Vampire Diaries universe.
The OC might be terrified at first. After all, being kidnapped by Loki is no joke. But they could also quickly gather their courage. Maybe they would try to talk to Loki, to understand his motives. If the OC is smart, they would know that Loki has his own reasons for doing things and might be able to find a way to reason with him.