Blake could be a great main character for an ancient kingdom fanfic. Her knowledge of the Faunus history might intersect with the history of the ancient kingdom. Maybe there were Faunus in the ancient kingdom and she wants to learn more about their role. Yang, with her strength and determination, could also be a main character, perhaps on a journey to find something in the ancient kingdom that could help her better understand her mother's disappearance.
Ruby could be a main character. Given her leadership skills and her connection to the silver - eyed warriors, she might be on a quest to uncover the secrets of the ancient kingdom that could be related to her powers. Weiss could also be a main character as her family has a long history, and she might discover some link between her family's past and the ancient kingdom.
The main characters could be a team of young Huntsmen and Huntresses who are sent to investigate the 5th kingdom. They might be a mix of established RWBY characters and new ones. For instance, a new character could be a mysterious figure from the fifth kingdom who has unique powers and a complex backstory that ties into the overall mystery of the kingdom. Maybe there's also an older mentor - like figure who has some knowledge about the fifth kingdom and guides the younger characters through their adventures there.
Ruby could be one of the main characters. Given her leadership skills and her inquisitive nature, she would be drawn to the mystery of the ancient nuclear weapon. She might see it as a potential solution to the Grimm problem or, on the contrary, as a great danger that needs to be stopped.
Perhaps there are also some new characters introduced specifically for this fanfic, characters who have a special connection to the ancient gods. They could be guides or guardians of the ancient god lore.
I'm not sure as it depends on the author of the fanfic. But it could be the main RWBY characters like Ruby, Weiss, Blake, and Yang. They are often the central figures in RWBY - related stories, so they might be the ones dealing with the ancient bomb.
Ruby could be a main character. Her speed and scythe - wielding skills would be really interesting to see in the Titanfall universe. She could quickly adapt to piloting a Titan and use her scythe in new and creative ways during battles.
Obviously, Team RWBY could be the main characters. Ruby could be the pilot or the one in charge of the mech's main weaponry. Weiss could handle the mech's ice - based defense systems. Blake could be in charge of stealth operations using the mech's cloaking features if it has any, and Yang could power up the mech's strength - related functions.
In a 'rwby meets god fanfic', Ruby, Weiss, Blake and Yang are the most likely main characters as they are the focus of the RWBY franchise. But depending on the direction of the fanfic, other characters like Penny or Jaune could also be important. Maybe Penny has some connection to the god due to her robotic nature, or Jaune could be the one who accidentally stumbles upon the god's arrival and then informs the RWBY team. Still, the RWBY girls will probably be the ones with the most significant interactions with the god.
Obviously, the members of Team RWBY - Ruby, Weiss, Blake, and Yang - could be the main characters. Their different personalities and fighting styles would make for an interesting exploration of different workout approaches.
Ozpin is a great choice. His long - lived nature means he has a lot of knowledge about the Great War and could be in a position to influence the events, either directly or through his students.
Blake would make a great main character in such a fanfic. Her past experiences and her ability to think on her feet could be very useful when interacting with the Pride Troopers. And perhaps Jiren from the Pride Troopers could be another main character. His incredible power would be a major factor in any battles or challenges they face.