As Dark Sakura, she rampages openly, managing to defeat Berserker by summoning Shadow Giants rivalling the Servants in power each and through the use of Saber Alter. In the day before the last one, she warns Shirou and Rin of the danger of awakening Angra Mainyou and asks them to run away, but they instead plan their own way to save her. Meanwhile, Sakura breaks free of Zouken's control and kills him with a combined attack with Kirei Kotomine. Shirou and Rin arrive, and with Rider's help, Shirou takes on Saber Alter while Rin goes off to confront Dark Sakura. Even though she was able to match her with the use of the Jewelled Sword of Zelterch, Rin was unable to kill her no matter how many times she's convinced herself. However, Sakura is later freed from Angra Mainyu's control when Shirou, who had defeated and killed Saber Alter beforehand, uses Caster's Rule Breaker on her.
When Sakura becomes Dark Sakura, her eyes turn from purple to blood red, and her hair turns white. She wears a black long-sleeved dress with blood-red linings, and her skin also gains extra blood red linings. Her fuschia hair ribbon also turns blood red.