It could be a reference to a certain character's look or attitude. Maybe there's a new character in the fanfic who has a steely gaze, and the author describes it as 'blue steel' to give a sense of mystery and cold determination. This character could be an ally or an enemy to Harry and his friends, adding a new layer of intrigue to the story.
Valyrian Steel could be part of an ancient prophecy in the Harry Potter fanfiction. Maybe it's said that only a wizard with a pure heart and a connection to the founders can wield a weapon made of Valyrian Steel. Harry, being the hero, is destined to find and use it to defeat the ultimate evil. It could also be that the Valyrian Steel is hidden in a different magical realm that Harry has to travel to, which would introduce new and exciting settings into the fanfiction.
In the context of Harry Potter fanfiction, 'Blue Steel' could have various interpretations. It could be a group or an organization within the wizarding world that the author has devised. For example, they might be a secret society with a particular agenda, perhaps related to protecting a certain magical artifact that has a blue - steel appearance. It could also be a magical creature with blue - steel like features, such as scales or fur, that plays an important role in the story.
It could be a metaphorical concept. In the fanfic, the idea of 'blue steel' might represent a character's inner strength. For example, Harry himself could discover his own 'blue steel' within him, which is his unwavering resolve to fight against evil, especially during a particularly difficult time when he faces a powerful and seemingly unbeatable foe.
It could be a magical item with a mind of its own. In fanfiction, the Blue Scarab might choose Harry as its owner and guide him through a series of challenges. It could have the ability to transform into different forms, like a key to open secret passages or a shield to protect Harry from dark spells. This would add an interesting dynamic to the story as Harry has to learn to communicate and work with this strange new entity.
I'm not sure exactly as it could cover a wide range of things. It might be a fanfiction that combines the world of Harry Potter with elements inspired by 'Arpeggio of Blue Steel'. Maybe it features characters from Harry Potter in a situation similar to the anime's plot, or it could use the unique concepts from 'Arpeggio of Blue Steel' to create a new magical adventure within the Potterverse.
You could make the succubus drain be part of a curse that was placed on Hogwarts long ago. Maybe it was put there by a dark wizard who wanted to weaken the school's magic. In the fanfic, the characters start noticing that students are getting weaker and tired all the time. They then discover the source is a succubus draining their energy, and they have to search through old books and magic spells to find a way to break the curse.
One way is to create a new Ministry department that deals with magical taxes. You could write about how this department audits wizarding businesses. For example, Ollivander's wand shop might be audited for taxes on the sales of wands. Another way is to introduce a tax on magical creatures. Hagrid might have to deal with the new tax regulations for his care of magical creatures at Hogwarts.
Well, 'Harry Potter' candy can be used as a plot device in fanfics. For instance, a poisoned candy could be sent to a character, leading to a mystery of who the culprit is. It could also be a way to show friendship, like when a character gives their favorite Honeydukes candy to another as a sign of loyalty.
In a more literal sense, if we think about a positive battery in a fanfic, it could be a new invention. Maybe a wizard in the Harry Potter world teams up with Tony Stark. They create a positive battery that uses both magic and technology. This battery could power a device that can nullify dark magic and the weapons of villains from both universes.
The defenestration spell could be incorporated as a key plot device. For instance, if there's a mystery about a series of 'window - related' incidents in Hogwarts, and Harry suspects the defenestration spell is involved. He then starts to investigate who might be using it and for what purpose.