I really like 'A New Path for Harry'. In this fanfic, Harry's abuse has made him more withdrawn, but when sorted into Slytherin, he finds a new family of sorts. The story focuses on his interactions with other Slytherins who initially have their doubts about him but come to respect him. It's an interesting take on how Harry could have thrived in a different house environment.
One great fanfiction in this vein is 'The Slytherin Heir' where Harry, having endured abuse, is sorted into Slytherin. It delves into his complex relationships with his housemates and how he overcomes the stigma associated with Slytherin. The story shows his growth and development as he uses his Slytherin cunning to face the challenges in the wizarding world.
I really liked 'Harry in Slytherin: A New Path'. It explores how Harry's values and actions might be different if he were in Slytherin. He has to deal with the Slytherin house's reputation and the prejudices that come with it. The author does a great job of showing how he might use his intelligence and cunning in a more Slytherin - like way.
I'm not sure of a specific title, but generally in such fanfics, the abuse Harry faces in Slytherin could be psychological, like being ostracized or bullied verbally. Some might explore how he tries to keep his Gryffindor values while dealing with this difficult situation in a house known for its more cunning nature.
There's a fanfic titled 'Harry in Slytherin: Overcoming Abuse'. In it, Harry's sorting into Slytherin is a shock to many. But within Slytherin, he finds a sense of belonging. The house's values of ambition and self - preservation help him deal with his abuse. The story shows how he transforms his pain into strength with the support of his Slytherin peers. It's a story of redemption and growth.
One interesting fanfiction could be 'The Slytherin Prince Harry'. In this story, Harry's sorting into Slytherin changes his whole Hogwarts experience. He has to deal with the prejudice from the Gryffindors while also trying to find his place among the Slytherins. It shows a different side of Harry, more cunning and politically aware.
One common theme is redemption. Harry, having been abused, often finds a way to redeem himself or be redeemed in the eyes of others through his actions in Slytherin. Another theme is identity. He has to grapple with his new identity as a Slytherin, which is different from the typical Gryffindor image of him.
One possible plotline could be Harry struggling to fit in at first. He's known for being a Gryffindor, so in Slytherin he'd face prejudice from both houses. Another could be him befriending Draco Malfoy early on and changing Draco's views. He might also discover a hidden side of Slytherin's history that helps him in his fight against Voldemort.
It makes him more cynical. Harry, after experiencing abuse, is less trusting when sorted into Slytherin. He uses the house's cunning to protect himself from further harm.
One great fanfic could be 'The Slytherin's Albus'. It shows Albus's journey in Slytherin, his struggles with the house's reputation and how he forms unique friendships. It's really interesting as it gives a new perspective on Albus compared to the original stories.
One great fanfiction is 'The Ravenclaw's Path'. It delves deep into how Harry's personality would be different if he were in Ravenclaw. It shows him making friends with Ravenclaw students who value knowledge and wit, and he gets involved in solving mysteries within the castle that are more related to academic pursuits rather than just the usual Gryffindor - centered adventures.
There's a fanfic where Harry is the heir of Slytherin and it focuses on his relationship with the Slytherin house. Instead of the usual enmity, he tries to bridge the gap between Gryffindor and Slytherin. I can't recall the exact name, but it's a really good read if you can find it. It shows Harry's growth as a character and how he uses his newfound heritage to bring about change in Hogwarts.