One interesting concept could be the combination of Hellsing's dark and gritty vampire lore with RWBY's unique world of Huntsmen and Grimm. For example, seeing how the powerful vampires from Hellsing would interact with the various characters in RWBY, like Ruby and her team. Maybe the vampires would be seen as a new type of Grimm by the RWBY characters at first, leading to some initial confusion and intense battles.
In a 'hellsing and rwby crossover fanfiction', a cool concept could be the sharing of combat styles. The precision and lethality of Hellsing's combatants, such as Alucard, could influence RWBY characters. RWBY characters, on the other hand, with their acrobatic and weapon - transforming fighting styles, might introduce new tactics to the Hellsing side. It could also be interesting to explore how the different power systems, like semblances in RWBY and the vampiric powers in Hellsing, would interact or clash.
One interesting concept could be the exploration of different power dynamics. For example, how Hans' unique abilities might interact with the supernatural elements in Hellsing. Maybe his skills could be enhanced or modified in the Hellsing universe, leading to new and unexpected storylines.
In this type of fanfiction, the concept of mixing the grittier, more militaristic feel of Halo with RWBY's more fantastical elements is really engaging. We could see UNSC soldiers trying to adapt to the Grimm - filled world of Remnant. And perhaps the characters from RWBY learning about the Forerunners and their technology. It could open up a world of possibilities for epic battles, new friendships, and the exploration of different values and ethics from both universes.
Character team - ups are also great. Like having Prompto and Yang team up. Prompto's sharpshooting skills combined with Yang's brawler style would make for an exciting duo. They could learn from each other in combat and in terms of personality, Prompto's more light - hearted nature could balance Yang's sometimes hot - headedness.
One interesting concept could be how Ichigo's powers interact with the unique abilities in RWBY. For example, his Soul Reaper powers might contrast or complement the Dust - based abilities in RWBY. Maybe his Zanpakuto could have an unexpected reaction when used in the RWBY universe.
One interesting concept could be Itachi's Sharingan abilities in the RWBY universe. His visual prowess might be used in unique ways during battles against Grimm. For example, he could use the Sharingan to predict Grimm movements more accurately, similar to how he reads his opponents in the Naruto universe.
Well, Link could be transported to RWBY's world during a time of great crisis, like when Salem is about to make a major move. His courage, which is a big part of his character, could inspire the RWBY team to face their fears more directly. And his knowledge of ancient magic from Hyrule might be the key to unlocking some hidden secrets in RWBY's world. For instance, there could be a long - lost relic in RWBY's world that only Link's magic can reveal, and this sets off a chain of events that involves both his quest and the RWBY characters' goals.
In RWBY Earth Crossover fanfiction, a cool concept is the way the Grimm would be perceived on Earth. Maybe the military would try to study them, thinking they are some new kind of bio - weapon. Also, the Huntsmen and Huntresses could become like superheroes on Earth, with people being in awe of their powers and skills.
One interesting concept could be the combination of Kirby's unique powers, like inhaling enemies and stealing their abilities, with the combat styles and semblances in RWBY. For example, Kirby might gain Ruby's speed semblance and use it in a creative way during battles in the RWBY world.
One interesting concept could be how Sans' unique abilities from his original game would interact with the RWBY universe. For example, his teleportation might be a new and unexpected skill in RWBY battles. Another concept could be the character interactions. Sans' laid - back personality could create some really fun and comical exchanges with the more serious or energetic RWBY characters like Ruby or Weiss.
One interesting concept could be the clash of different powers. In RWBY, characters have unique abilities like semblances, and the Reaper has its own set of death - dealing powers. A crossover might explore how these powers interact when the two universes collide. For example, how would Ruby's speed and scythe - wielding skills compare to the Reaper's? Another concept could be the meeting of different character personalities. RWBY characters are often young and idealistic, while the Reaper is a more menacing and mysterious figure. Their interactions could lead to some really engaging storylines.