Guan Suo is Guan Yu's biological son who accompanies his father and older brother in Shu's version of Fan Castle. He prepares the troops for the castle assault. When they are surrounded by enemy troops, he tries to protect his father during their escape. Reaching a cliff overlooking a river, Guan Yu decides to sacrifice himself for his son's safety by pushing Guan Suo into the raging waters below. Guan Suo returns to Shu and appears in Yi Ling in an attempt to avenge his father's death. After the battle, he appears again in Jin's Story Mode to continue defending Shu. Like other surviving warriors for Shu, he dies in battle during their final defense at Cheng Du.
His first Legendary Mode entails his escape from Wu, continuing from Fan Castle in Story Mode. As he fights for his survival in Jing Province, he meets and rescues a mysterious girl who introduces herself as Bao Sanniang. After explaining a bit of his history as he protects her, Guan Suo expects her to return home after the battle. She instead fawns over his heroic charisma and follows him
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.