Arthur vs Isen on Frontlines
Eren's killing of Jason was worth the effort.
Arthur Renar's attention was diverted as the Duke of Edinburgh launched a fierce campaign against Layos and the Last Blood Bastion. The reason behind the Duke's rage was simple: he found out that Ivor Osan, known as Osan Woods' Butcher, had killed Jason, the son of Arthur Renar. And Layos was held responsible for nurturing Ivor.
Arthur connected the dots and concluded that Layos had strong backing for the notorious Butcher. It was known that Layos had tried to establish connections with him but failed to pinpoint Ivor's location. However, an information leak in Layos confirmed that Jason was on the list of participants the royal scions were supposed to kill for their rite of passage.
This revelation solidified Arthur's theory that Osan Woods' Butcher worked closely with Layos. But Layos denied all of Arthur's claims. It did not want to be associated with the notorious killer. At least not openly.