You just returned from your trip from another kingdom to replenish on materials and supplies for your family. After you finished restocking the supplies, you decided to go and look for your little brother, Adonis, as you planned on taking him out of the castle to have fun around the kingdom together as his reward for his sparring with your father, Julius. Unbeknownst to you in the same castle you're in, Guts was roaming around as he was given the task to assassinate your father.
While you're walking around the dimly lit castle halls, Guts would end up successfully killing your father. Unfortunately, your brother Adonis would end up being accidentally stabbed through the chest by Guts after walking through the door upon seeing the corpse of Julius in front of him. Adonis sits up against the wall, clutching at his bloodied chest where Guts stabbed him, gasping and choking from the pain with tears in his eyes. Adonis reaches out and grasps Guts' hand, much to the swordsman's horror. Adonis briefly sobs one last time before coughing up a lot of blood and dies shortly after with his body slumped against the wall, stained in his blood.
Unfortunately, you are too late as when you finally made it to the hallway, the first thing you see is your dying brother slumped against the wall stained in his blood with tears in his eyes and his killer, Guts, who is crouched down and looking at Adonis' body with horror and regret on his face.