In a fanfiction like this, perhaps there is a prophecy in the wizarding world that foretells the arrival of a being with great power from another realm, which is Superman. The Ministry of Magic tries to keep his existence a secret, but Harry Potter discovers him. They find that their enemies, like Voldemort and Lex Luthor (who some how also enters the wizarding world), are working together. Harry and Superman then have to find a way to stop them. Superman's heat vision and super speed combined with Harry's spells like Expelliarmus and Patronus could create some really exciting battle scenes.
The interaction could be really interesting. For example, Dumbledore would be very diplomatic in dealing with Superman. He would see the potential good in him but also be cautious. Superman would respect Dumbledore's wisdom. Harry could show Superman the secrets of Hogwarts, like the Room of Requirement. Superman could in return show Harry his Fortress of Solitude. When it comes to fighting, Superman could use his strength to take on the more physically powerful dark wizards, while Harry and his friends use magic to deal with the more magically inclined threats. They would learn from each other's strengths and weaknesses.
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.
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.
The character interactions are also interesting. Imagine Harry's cautious and sometimes rule - following nature with Max Steel's more adventurous and risk - taking attitude. Their conversations and how they grow to understand each other can be a great part of the fanfiction. For example, Max might introduce Harry to some new ways of thinking outside the box of magic, and Harry could show Max the depth and complexity of the magical world.
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.
One interesting crossover could be the use of magic in the Max Steel world. For example, Harry Potter characters could bring their spells to help Max Steel in his battles against villains. Maybe they could use the 'Stupefy' spell to stun the bad guys that Max Steel usually has to fight physically.
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.
Often, the 'nightmare man' is an antagonist in the fanfiction. He could be a figure from the past, a forgotten wizard who was once defeated but has now returned with new powers related to nightmares. For instance, he might have the ability to make people relive their worst memories in their dreams, weakening them in the real world. This makes him a formidable foe for the heroes of the story.
Well, it could be a variety of things. It could be a villain who uses dream - related magic to torment people. For example, he could enter people's nightmares and manipulate the events there to drive them to despair. It might also be a misunderstood character who has a power related to nightmares but is not truly evil. In some fanfictions, the 'nightmare man' could be a symbol of the characters' inner fears made manifest.