No. Harry Potter is a completely separate and original fictional universe created by J.K. Rowling, while Fate Stay Night is another distinct work. They have their own unique storylines, characters, and settings, and there is no such relation of Harry Potter being a fanfiction of Archer Fate Stay Night.
The settings are different. Harry Potter is set in a wizarding world with places like Hogwarts, Diagon Alley, and the Forbidden Forest. Fate Stay Night is set in a modern - day Japanese city with a hidden world of the Holy Grail War. Also, the characters are distinct. Harry Potter has characters like Harry, a young wizard, and Dumbledore, a wise old wizard. Fate Stay Night has characters like Shirou, a normal high - school student turned Master, and Saber, a powerful Servant.
Archer is one of the Servants in Fate/stay night. He has a complex personality. He is a skilled archer, of course, with high - level combat abilities. His real identity is actually a future version of one of the main characters, which adds a lot of depth to his character and his interactions within the story.
One common theme is the exploration of different magical systems. Since both Harry Potter and Fate Stay Night have their own complex magic, fanfictions often explore how these magics interact or compare. For example, how the spells in Harry Potter would fare against the magecraft in Fate Stay Night.
One interesting Archer fanfiction could be 'Archer's Redemption'. In this story, Archer has to face his past mistakes in a new and unexpected way. It delves deeper into his character, exploring his internal conflicts and how he tries to make amends for what he has done in different timelines. Another great one is 'Archer and the Lost Grail'. This fanfic takes Archer on a quest to find the true meaning of the Grail, which is different from the typical Grail War scenarios we see in the original work. It's full of mystery and adventure.
There is also 'In the Company of Archer and Rin'. This fanfiction focuses on their daily lives together after the events of the main story. It shows how they support each other, from Archer's combat advice to Rin's magical knowledge sharing. It's a heartwarming read that delves into their characters.
Another theme is adventure. Writers might create scenarios where Rin and Archer go on quests together, facing various challenges that test their bond and abilities. This can range from battling new enemies to solving magical mysteries.
One common theme is the exploration of Archer's complex personality. The OC often serves as a catalyst for this exploration. Another theme is the power dynamic between Archer and the OC, especially if the OC is a mage or has some special ability. Also, there's often a theme of redemption or self - discovery for Archer through his interactions with the OC.
He could be a wild card. Maybe he has different motives from his original role. For example, he might be trying to change certain events that he regretted in his own timeline.
One popular one could be 'Archer's New Adventure in a Crossover World'. It often features Archer in unexpected situations in a crossover setting, with interesting character interactions.