Sheva Alomar is Chris Redfield's main playable partner in Resident Evil 5.
Sheva is a member of the Bioterrorism Security Assessment Alliance, or BSAA, and works with Chris during his mission in the fictional African region of Kijuju. Her background as a BSAA operative gives the campaign a local perspective while Chris investigates a new bioterror threat.
Players can control Chris in the standard campaign, while the computer controls Sheva, or they can play cooperatively with a second player. This two-character structure was a major design feature of Resident Evil 5 and followed the cooperative direction introduced by earlier series experiments.
Sheva is sometimes mistaken for Jill Valentine because Jill is also closely connected to Chris and appears in the game. Jill, however, is a major story character rather than Chris's regular campaign partner. Claire Redfield and Rebecca Chambers do not fill that role in Resident Evil 5.