I don't know for sure without reading it. However, in RWBY, it could be the main RWBY girls - Ruby, Weiss, Blake, and Yang. Since they are central to the RWBY story and often use blades or weapons in combat, they are likely to be the main characters in this fanfiction as well.
I'm not entirely sure as I haven't read it specifically. But generally, in RWBY fanfictions, 'life with blades' could potentially be about characters' lives intertwined with the use of their weapons (blades). It might explore how the characters' daily existence, battles, and relationships are affected by their blades.
The main characters are Blades and Bumblebee, of course. Blades is known for his certain characteristics, and Bumblebee has his own distinct traits as well.
Often, Naruto himself is likely to be one of the main characters. He might be drawn to the power of the Blades of Chaos and try to use them for the good of the village.
I'm sorry, I don't know who the main characters in the 'Blades in Black Novel' are as I haven't read it.
I'm not entirely sure as I haven't read it in full, but they could be hardened criminals.
In addition to the main RWBY team, there could be other important characters. Ozpin might play a role, as he often does in RWBY stories. He could be guiding the characters through the trials they face. Also, characters like Penny or Pyrrha could make appearances and contribute to the plot in some way in this 'Trials in Life RWBY fanfic'.
I'm not sure specifically as there are many possible interpretations in fanfiction. It could still feature Ruby, Weiss, Blake, and Yang as main characters, but with a plot centered around dilation. For example, Ruby might be the one to first notice something strange related to dilation and lead the team to investigate.
I don't know for sure without reading it, but it could feature the main RWBY characters like Ruby, Weiss, Blake, and Yang. Since it's a fanfiction, there might also be an original character who is the'stray' that the story focuses on, and this new character could interact with the main RWBY quartet.
Obviously, Cliffjumper is one of the main characters. In most of these fanfictions, he is the one bringing his unique set of skills and personality into the RWBY universe. Then there are the main RWBY characters like Ruby, Weiss, Blake, and Yang. Ruby with her leadership and scythe - fighting skills, Weiss with her Glyphs and swordplay, Blake's stealth and katana - using abilities, and Yang's brawler - like combat style often interact with Cliffjumper in different ways in the fanfictions.
In most 'rwby yellowbeard fanfiction', Yellowbeard takes center stage. He's the one with the unique look and backstory. But the RWBY girls are essential too. Ruby with her leadership skills, Weiss with her grace and combat abilities, Blake with her stealth, and Yang with her strength. There may also be other characters from the RWBY universe that pop up, like Professor Ozpin or Qrow Branwen, who might interact with Yellowbeard in different scenarios.