Perhaps he battles a horde of dementors led by a rogue Death Eater. Harry uses the sword's magic to fend off the soul - sucking creatures. The sword's light could act as a repellent to the dementors' dark presence.
He could engage in a battle against a powerful dark wizard. For example, a fight with a resurrected Voldemort who has some new dark magic. The sword, being a powerful weapon, might be the key to defeating him.
It could have the ability to communicate with Harry on a psychic level. Telling him when danger is near or guiding him on how to use its powers most effectively in different situations.
The dragon sword in the fanfiction might be long and slender, with a blade that shimmers like dragon scales in the sunlight. The hilt could be made of a dark, enchanted metal, perhaps with a dragon's head carved at the end, its eyes seeming to glow with an inner fire.
The dragon sword might give Harry Potter enhanced combat abilities. It could potentially allow him to cut through dark magic defenses more easily, much like how the Sword of Gryffindor could destroy Horcruxes. Maybe it gives him the power to communicate with dragons, since it's a dragon sword, and use their strength in battles against Voldemort and his Death Eaters.
A RWBY character with the Sword of Gryffindor might also experience a change in their personality or outlook. Since the sword is associated with Gryffindor values, the character could become more courageous and noble. They might also start to uphold values that are more in line with the Harry Potter universe, which could create an interesting dynamic within the RWBY world.
Love for Lily. Since Harry is Lily's son, Snape might hold Harry to keep him safe out of his lingering love for Lily. He doesn't want to see Harry come to harm, so he takes extreme measures like holding him in a secure place.
When Harry Potter wields Excalibur in fanfiction, the story's power balance shifts. Excalibur's power is not just physical but also has a sort of magical aura. This could enhance Harry's own magical presence. It might lead to new adventures as he tries to understand the sword's full capabilities. He may also face new enemies who are interested in the sword. For instance, ancient magical beings who have a connection to Excalibur might come into play. And his relationships with his friends could also change as they adjust to this new, more powerful Harry.
Well, if Harry Potter wields Mjolnir in fanfiction, it would be an absolute power explosion. Harry already has his magic skills from the wizarding world, and adding the power of Mjolnir would make him nearly invincible. He could use the hammer's lightning - based powers along with his spells, creating some really unique and powerful combat combinations. It would also change the dynamic of his relationships. His friends might be in awe, and his enemies would be even more terrified.
Well, it could be really cool. Yamato is a powerful weapon. Harry Potter is already powerful with his magic, but adding Yamato to the mix would make him almost unstoppable. He could use the sword's abilities along with his spells to defeat enemies in a very unique way. Maybe he could use magic to enhance the sword's power even further.
Well, if Harry Potter wields Excalibur in fanfiction, it would be a wild combination. Harry is already a powerful wizard, but Excalibur is a sword of legend. It might change the whole dynamic of the wizarding world. For example, the sword could cut through dark magic in a way his wand can't. Maybe it would attract the attention of other magical creatures who respect the sword's power. And it could also create some interesting relationships with Arthurian legends within the Harry Potter universe.
Hermione would surely be one of the first to help. She is highly knowledgeable in magic and would likely try to use a healing spell or find a potion to stop the bleeding.