By comparison XCOM 2 and the Alien Hunters DLC is far more demanding than its predecessor XCOM: Enemy Unknown. While the top-down viewpoint and turn-based nature suggests suggests otherwise, XCOM 2 - Alien Hunters will take advantage of capable GTX 900-series and Radeon R300-series graphics cards. Beware the MSAA option, even the GTX 980 Ti struggles with this forced downsampling effect.
XCOM 2 - Shen's Last Gift is the third DLC add-on for XCOM 2. It adds a new story mission and a new soldier class.