Cortana

Cortana is a fictional artificially intelligent (AI) character in the Halo video game series. Voiced by Jen Taylor, she appears in Halo: Combat Evolved and its sequels, Halo 2, Halo 3 and Halo 4, in the prequel and epilogue of Halo: Reach, and several of the franchise's novels and comics. During gameplay, Cortana provides backstory and tactical information to the player, who assumes the role of Master Chief Petty Officer John-117. In the story, she is instrumental in preventing the activation of the Halo installations, which would have destroyed all sentient life in the galaxy.