Ruby herself could have major revelations. Since she's the main character, seeing different versions of herself and different ways her story could have gone might make her question her own path and purpose.
Blake could also be a likely candidate. Given her complex backstory and her struggle with her identity, seeing alternate versions of herself in different multiverses could give her new insights into who she is and what she wants to be. Maybe she'll see a version of herself that fully embraced her Faunus side in a positive way and it'll inspire her.
Well, Weiss is quite popular in RWBY Multiverse Fanfiction. Her growth as a character, from a somewhat spoiled heiress to a strong fighter, is explored in different ways in the multiverse. Ruby is always a top pick too. Her determination and unique abilities like her speed and scythe - wielding skills are fun to play around with in different multiverse settings. And Pyrrha, even though she had a tragic end in the original, is often resurrected or given different fates in fanfiction, which makes her popular as well.
In 'rwby reading the multiverse fanfic', the main characters would surely include Ruby, Weiss, Blake, and Yang. But it could also feature other important characters from RWBY like Ozpin or Qrow. Since they are all part of the RWBY universe, they might get dragged into the multiverse adventures as well. Maybe they would play important roles in guiding the main girls or helping them understand the new universes they find themselves in.
Obviously, Ruby, Weiss, Blake, and Yang are likely to be the main characters. Since it's RWBY - related, they would be the central focus as they watch the events in the multiverse. They are the ones whose reactions and interactions with the multiverse would drive the story forward.
Blake could also be a great character to focus on. Given her own complex backstory and her tendency to be more introspective, she might have deeper insights into the characters and situations in the Undertale AUs. She could form unique relationships with some of the more morally ambiguous characters in the Undertale multiverse.
One cool plot twist could be that in one of the multiverse scenarios, their enemies are actually their allies. This would completely turn their understanding of good and evil on its head and force them to reevaluate their relationships. It could lead to some really intense character development as they try to figure out what this means for their own world.
Ruby is often very popular in RWBY multiverse fanfic. Her unique weapon and her role as a leader make her a central figure. Blake also has a lot of fans in fanfics as her backstory and her struggle with the White Fang can be explored in many different multiverse scenarios. Yang too, with her powerful Semblance and her protective nature towards Ruby, is a favorite among many fanfic writers.
The most interesting characters in 'RWBY Watches the Future Fanfiction' are likely to be RWBY for starters. Ruby's wide - eyed wonder at the future, Weiss's attempts to rationalize it, Blake's more pensive approach, and Yang's bold reactions make them captivating. However, if there are future versions of themselves or their friends, those would be really engaging. Imagine seeing an older, more experienced Ruby or a Weiss who has changed significantly due to future events. And of course, any new and mysterious characters that are part of the future they are shown could also steal the show, with their unknown backstories and potential roles in the future world.
Ruby is a likely candidate. She's already a skilled fighter with her scythe, and her eagerness to learn new techniques would make her adapt well to Santoryu. Her speed and agility could be enhanced with the three - sword style.
Ruby is a likely winner. She has her powerful scythe, great speed, and strong leadership skills. Her ability to quickly analyze a situation in battle gives her an edge. Weiss also has a good chance. With her Glyphs and powerful summoning abilities, she can control the battlefield. Blake is another one. Her speed and shadow - cloning ability make her a tough opponent. And Yang with her super strength and ability to take a hit and then counterattack fiercely could also be a top contender.
In addition to RWBY, other important characters like Qrow or Ozpin could also be focused on. Qrow has a lot of history and his own future could be intertwined with RWBY's. Ozpin, with his vast knowledge and secrets, might also play a crucial role in how they view the future. His wisdom could be used to help them understand what they see, or he might also be a part of the future they witness in unexpected ways.