Halo 5: Guardians launched in 2015, and continues the series of first-person shooters on Xbox and PC. In it, Master Chief and his rogue Blue Team must stop Cortana from wreaking havoc on the galaxy.

The Coalition's upcoming prequel game Gears of War: E-Day may be able to avoid some controversy seen with another Xbox prequel: Halo ... actions taken by the A.I. Cortana and the Spartan Master ...

Cortana was unveiled in 2014 as a virtual assistant for Windows phones. It was named after the advanced artificial intelligence guide in Microsoft's then best-selling Halo game series. Three years ...