Guan Suo is a young man who takes his duties very seriously. Compared to his stern father and older brother, Guan Suo is a bit light-hearted and is a little wet behind the ears. Even if he doesn't always believe in himself, he uses earnest effort to overcome any shortcomings he thinks he may have. He seeks to someday become a warrior worthy of his father's name. Born with a handsome constitution, he may unintentionally attract members of the opposite gender. He compliments the ladies he encounters, voicing his honest praise without sarcasm or jest as a gesture of politeness. According to the soldiers at Fan Castle, he is extremely popular with the ladies in Shu. Guan Suo speaks with a relatively modern day dialect in the Japanese script as a contrast to Guan Ping and his father, using courtesy if needed.
Like Guan Ping, he strives to become the spitting image of his father. However, he feels he is inept to follow in his father's complete footsteps. Guan Yu assures his son that he is proud of him, no matter how he decides to raise himself as a warrior and encourages his son to follow his own path in life. Guan Suo shares a close brotherhood with Guan Ping, as the united brothers' vigor is viewed as the pride of Shu's army.
Although they met by pure coincidence, Guan Suo is happy to have met Bao Sannaing since she offers him light-hearted optimism and support. While he continues to struggle with his self-image and expectations for his future, Guan Suo is confident that he is at least strong enough to protect her from danger. Her enthusiasm in battle inspires him to try harder as well.