Well, a great plot for a Harry the Grimm fanfic could involve Harry getting lost in a strange and dangerous part of the Grimm realm. He has to use his wits and any skills he has learned to find his way back. Along the way, he meets different Grimm characters who either help or hinder him. It could also be interesting if Harry somehow gets involved in a power struggle between two powerful Grimm factions.
One idea could be Harry discovers a hidden power within the Grimm world that no one else has. This new power could lead him on a journey to uncover secrets about the origin of the Grimm. Another idea is Harry befriends an outcast Grimm creature and together they face the prejudices of the Grimm society.
A possible plot for a Harry the Grimm fanfic could be that Harry is given a mysterious task by an old and wise Grimm being. The task seems impossible at first, but as he delves deeper into it, he realizes it's related to saving the Grimm world from a looming threat. He has to gather a group of unlikely allies, including some who were once his enemies, and together they train and prepare to face this great danger. This could involve exploring different regions of the Grimm world, learning about its unique magic and lore, and ultimately growing as a character while also saving the day.
One idea could be Ruby facing a new type of Grimm that has unique abilities, like the ability to manipulate time in a small area. This would put Ruby in a tough situation where she has to figure out how to combat it while being affected by the time distortion. Another plot could involve Ruby getting lost in a Grimm - infested area and having to rely on her wits and the little resources she has to survive and find her way back to her team.
One idea could be that the characters have to face a new type of Grimm that has emerged from the Pacific region. These Grimm could have unique abilities like being able to camouflage in the ocean or use water-based attacks. Another plot could involve the team having to form an alliance with a local group in the Pacific area who have their own ways of dealing with Grimm.
One idea could be that the Grimm creatures start to appear in the wizarding world. Harry and his friends have to use both magic and knowledge of Grimm lore to fight them. For example, they might discover that some dark magic has opened a portal between the two universes.
One idea could be to combine the magical world of Harry Potter with the dark and fairy - tale - like elements of Grimm. For example, having the characters from Harry Potter encounter Grimm - inspired creatures in the Forbidden Forest. Maybe a werewolf - like creature similar to the ones in Grimm tales that has a different set of magical abilities.
A plot idea could be that the Sisters Grimm discover a hidden realm within their own world that has all the forgotten or lost fairy - tales. They then have to figure out how this realm is connected to the problems in their own town. Also, a story where they swap powers or abilities for a day and have to deal with the chaos that ensues. For example, if Sabrina has Daphne's ability to see the good in people and Daphne has Sabrina's more cynical view, it would lead to some interesting character development.
One idea could be a story where a powerful Demon Grimm is awakened by an ancient ritual gone wrong. The main characters in RWBY have to team up with unexpected allies to defeat it. They might discover new powers or abilities within themselves during the battle.
One idea could be a story where a humanoid Grimm has the ability to blend in with humans and is on a mission to infiltrate Beacon Academy. It could create chaos by spreading false information among the students. Another idea is a humanoid Grimm that has a strange bond with a Huntsman, and they have to figure out if they can trust each other or not. And perhaps a humanoid Grimm that is actually a failed experiment of some sort of dark magic, and it's trying to find its place in the world of Grimm and humans.
One idea could be Harry getting involved in Gremory family politics. He could use his unique skills and knowledge to help resolve internal disputes within the family.
Well, a plot could revolve around Harry accidentally awakening the mummy and then having to deal with the chaos that follows. The mummy might start causing strange things to happen in the town, like making the water turn to sand or the plants wither. Harry then has to find a way to reverse the mummy's awakening or at least control its actions. He could search for an old spell book that might have the answers.
One idea could be that Harry, being a playboy, gets involved in a series of high - society parties and romances. He might meet a mysterious woman who challenges his playboy ways and makes him question his lifestyle.