Ainz remains the central figure. He's constantly evolving in his role as the Overlord. In volume 6, we also see more of his subordinates. Characters like Albedo continue to be important. She is extremely loyal to Ainz and often plays a crucial role in handling various affairs within the organization that Ainz leads. There could be other minor characters who are part of the different political or power - related groups that get introduced as well.
Ainz is still one of the main characters, of course. His actions and decisions drive a lot of the plot. There might also be some new characters related to the various factions that are introduced, but I can't recall their specific names right now. But generally, they play important roles in the power struggles and conflicts within the story.
In Overlord volume 6 light novel, the main character we can't ignore is Ainz. He's on a journey of ruling this new world. Alongside him, some of his key subordinates are significant. Albedo, for instance, is always by his side, helping him with different matters. And then there are characters from the opposing factions, though not as detailed as Ainz and his group, but they also contribute to the overall story by creating challenges and conflicts for Ainz to face.
One important character could be new adversaries that Ainz and his group face. These characters bring new challenges and often have unique abilities or motives. Another might be some minor characters within the native population of the new world that help to flesh out the world - building aspect.
Since I haven't read volume 14 in detail, I can't say for sure who the new characters are. But it's possible that there are new members of a guild or organization that Ainz has to deal with. These characters could bring new dynamics to the story, whether they are powerful warriors, cunning mages or something else entirely.
In this volume, the Lizardmen leaders such as Crusch Lulu are important. They represent the native species that Ainz has to deal with. Among Ainz's subordinates, Demiurge also stands out. He is very intelligent and his strategies and ideas are important for Ainz's plans. There are also other minor characters among the lizardmen tribes that add to the richness of the story.
I'm not entirely sure which new characters are introduced specifically in volume 9. But generally, in the Overlord series, characters like Ainz Ooal Gown remain extremely important. His actions and decisions drive most of the story. The floor guardians such as Albedo also continue to be significant as they carry out Ainz's orders and protect Nazarick. There may be some minor characters from the human kingdoms or other races that are introduced to show the different perspectives in the world.
I don't have the specific information about new characters in Volume 15. But it's possible that there are new characters related to the religious or cultural aspects of the world in the light novel. Maybe there's a new high - ranking priest or a scholar who has knowledge about some long - lost secrets. These new characters would then interact with Ainz and his comrades, creating new storylines and conflicts.
Ainz Ooal Gown is the main character. He was a normal gamer in the real world but becomes a powerful undead overlord in the novel's world. Albedo is another important character. She is fiercely loyal to Ainz.
There are likely other important characters as well. Maybe some of his loyal followers like Albedo or Shalltear Bloodfallen. Their loyalty and how they assist Ainz are often part of the story in the Overlord series.
Ainz Ooal Gown remains the most important character. His decisions and actions drive the plot forward. He is constantly strategizing about how to expand his influence in the new world.
I'm not entirely sure about brand - new characters specifically in Vol 8, but existing important characters like Ainz Ooal Gown continue to be central. His actions and decisions drive the plot forward.
One important character introduced could be some of the new leaders of the local factions in the New World. They play a role in the political and military aspects that Ainz and his forces interact with. For example, there might be a new king or a powerful general.