Diamondback/Mizuchi is a prominent generic under Orochi's services, who has managed to be often kept in command of some of Orochi's other generals, despite showing no amounts of marital prowess or strategic accomplishment. While not yet a fully fledged character, his role is greater than the likes of Dodomeki and Gyuki.
Role in games
Throughout the Warriors Orochi series, Diamondback is a regular frontline general in the armies of Orochi. Warriors Orochi 2 often sees him executed by Orochi during the final battles of the kingdom story modes, due to his cowardice and reluctance to fight, which rallies and spurs Orochi's forces to throw themselves to their demise.
It is in Warriors Orochi 3 however, where he is most prominent, first appearing at Shouchun positioning himself away from danger and tells Shuten Doji to do his dirty work for him, with the redheaded demon easily beating back the resistance forces. Once the resistance breaks through, he sets fire to his castle and begins to flee. Diamondback is also seen at Hasedo where he stays in the castle and tries to withdraw to the southeast telling Shuten Doji to demolish a central bridge and take out Taigong Wang. Next he appears at Xuchang allied with Dong Zhuo's forces and stays back from the battle, once again retreating when Dong Zhuo is defeated and telling Shuten Doji to accompany him. When Shuten Doji is captured however, Diamondback decides to head back to Luoyang. He also acts as the commander for some demon armies during the side stages as well, especially if there is no other characters from the demon forces around.
In Warriors Orochi 3 Ultimate he is reduced to a mere frontline officer under Da Ji when she allies herself with Tamamo and performs no exceptionable feats during the story. However, a new stage details his first meeting with Shuten Doji, at Shouchun, where they, along with Dodomeki and Gyuki defeat a coalition guarding the castle including the likes of Cao Ren. A DLC stage set at Koshi Castle from the first two games has Diamondback as a ringleader of a rebellion against Orochi, to which the Oda and Yoshihiro Shimazu assist him with, only to find him often retreating or backing out when pressured by Kiyomori Taira. Whether he commits himself fully or betrays you depends on the player's actions throughout the stage. When Keiji searches for his theme at Chibi, Diamondback tries having the Hydra's theme to himself only to be defeated and called out for stealing music by Keiji.
Personality
Smug, condescending and cowardly, Diamondback is someone who thinks he is far greater than he actually is, showing himself to be a step or two above his fellow associates and berating those who help him like Shuten Doji.
Trivia
Diamondback is based on a Diamondback snake.