Gan Ning
Even though Gan Ning saved Huang Zu's life at a critical moment, Huang was unappreciative of his effort because he despised Gan for his background (Gan Ning used to be a pirate). Gan Ning then heeded the advice of his comrade, Su Fei (蘇飛), to defect to Sun Quan's side, bringing along with him confidential intelligence on Huang Zu's forces. Sun Quan received Gan Ning warmly and followed Gan's suggestion to launch a full assault on Huang Zu again three years later in 208, starting the subsequent Battle of Jiangxia.