Another way is through a shared goal. Maybe there is an artifact or power source that both Salem (for her own evil purposes) and some characters from Worm and RWBY (for good) are after. This would lead to a complex web of alliances and betrayals as they all try to get their hands on it.
A simple way could be through a dimensional rift. A character from RWBY accidentally stumbles into the Worm universe or vice versa. Then they have to figure out how to get back while dealing with each other's worlds' problems.
One idea could be Salem's reaction to the powers and technology in the Worm universe. Maybe she tries to use some of the parahuman abilities or advanced tech to further her own goals in the RWBY world.
Well, without actually reading the fanfic in full, it's hard to give a complete review. But generally, if it combines elements like 'Asunder Worm' and RWBY's 'Prism' and 'Nevermore', it could be a really interesting mix. It might explore new storylines within the RWBY universe, perhaps with a new take on the Grimm like Nevermore, and bring in some unique concepts from Asunder Worm. However, the quality would also depend on the writing skills of the author, such as how well they handle the characters, the pacing of the story, and the integration of these different elements.
One thing that might make it unique is the combination of different fictional elements. Asunder Worm has its own set of concepts and RWBY has a completely different world. The Prism and Nevermore from RWBY are very distinct. When combined with Asunder Worm, it could create a story that's not like any other RWBY fanfic. For example, the way the fanfic might handle the power dynamics related to the Prism in the context of Asunder Worm's mechanics could be very different from a typical RWBY story.
The RWBY characters could interact with Slender Man in various ways. For example, Ruby might be the first to sense something is wrong due to her keen senses. She could try to attack him directly but find that her attacks seem to pass through him. Weiss could use her glyphs to try and contain or at least slow him down. Blake might be more cautious, observing his behavior from a distance to figure out his motives. Yang, on the other hand, would probably charge in head - first, only to realize that brute force doesn't work against him.
The main difference is the addition of alchemical solutions. While 'worm' is mainly a science - fiction story, the fanfic brings in the concept of alchemy which is more related to the transformation of substances and often has a touch of the mystical. So it changes the power dynamics and the overall feel of the story.
The main difference is the deviation from the original plot. In 'canon divergence worm fanfic', the story takes a different turn, while the original 'Worm' follows a set path. For example, a character's death in the original might be reversed in the fanfic.
Weiss and Iron Man could have an interesting dynamic. Weiss is from a wealthy family in RWBY, and Iron Man is a billionaire. They could bond over their knowledge of high - society and use their resources to fund new projects together. Maybe they create a new type of Dust - powered armor for the RWBY characters.
The characters from the Worm Universe might interact with Earthlings in a rather complex way. Some might view Earthlings as weak and in need of protection or control. Others could see them as potential allies or a source of new resources. For example, a powerful cape from the Worm Universe might try to recruit Earthlings with certain skills to join their cause.
A good RWBY Salem fanfic often has a deep exploration of her character. It should show more than just the 'evil villain' side. For example, it could explore her past traumas or her reasons for her actions. This makes her more three - dimensional.
In a Worm fanfic, acceleration can be portrayed in various ways. For example, it could be the acceleration of a character's powers as they gain more experience or face extreme situations. A cape might have an ability related to speed, and the acceleration of that speed could be described during a battle, like suddenly being able to move twice as fast as before, which would create a more dynamic and exciting fight scene.