The central plot of the "Noblesse" anime revolves around two main conflicts: the battle against the Union and the internal strife within the Noble society of Lukedonia. The Union's pursuit of Rai is driven by their desire to capture the powerful Noblesse and exploit his powers. This leads to confrontations with modified humans like M-21, who eventually defects after Rai saves him and awakens his latent werewolf abilities, revealing his past as part of the Union's failed experiments.
The second major conflict is with Lukedonia, Rai's homeland. The current Lord, Raskreia, believes Rai betrayed their people and is responsible for the death of the previous Lord, who was her father. She sends clan leaders Regis and Seira to investigate him. The climax reveals a profound misunderstanding: the previous Lord, weary of his long life, orchestrated his own 'eternal sleep' with other clan leaders who were loyal to him, wanting to pass the burden to a new generation. He had wanted Rai to succeed him, but Rai refused the position. Raskreia's aggressive actions stem from grief and misinformation fed to her by traitorous clan leaders. Rai is forced to confront her and the loyalist Royal Guards not as an enemy, but to reveal the truth. In doing so, he expends a massive amount of his life force, resolving the conflict and clearing his name but leaving him severely weakened, with his ultimate fate left ambiguous at the series' end.