Dead or Alive 4

Dead or Alive 4 (DOA4) is a fighting game developed by Tecmo and released on December 29, 2005 for the Xbox 360 video game console. As the latest entry in the Dead or Alive video game series produced by Tecmo's Team Ninja studio, its plot follows the events of the 2001 title Dead or Alive 3. The game features twenty-two playable characters and many multi-tiered and interactive fighting arenas.

Dead or Alive 4 focuses on the story of Helena, the young woman taking over the mantle of DOATEC as its second chairman.

Halo Player
DOA4 contains three new playable characters. Kokoro, a young Geisha in training, Elliot, a 16 year-old boy from England and protégé to Gen Fu, and La Mariposa, a female Lucha Libre wrestler and rival to Tina.

In addition, DOA4 features a playable unlockable character from the Halo series. The November 2005 issue of Game Informer revealed that this character is a female Spartan supersoldier, going by the name Spartan-458. It would later be revealed that her real name would be "Nicole". In conjunction, a Halo-themed stage named Nassau Station is incorporated in the game.