The episode of King of Beasts GoLion used to create this episode of Voltron is titled "Brave Shirogane's Brother". In that episode Princess Amue (Romelle in Voltron.) falls into the pit and is rescued by Ryou Shirogane, the younger brother of Takashi Shorigane (The original Blue Lion pilot who was murdered in the episode "Death of Shirogane the Hero".). Ryou is oblivious to the fact that Honerva (Haggar in Voltron.) murdered his brother. When Amue tells him, he swears revenge and joins the fight against the Galra Empire.