http://www.pcgamer.com/xcom-2-war-of-the-chosen-review/

What is it? Massive expansion that adds new nemesis bosses, resistance factions, resistance heroes, and sweet shoulder pads.Expect to pay £35/$40Developer FiraxisPublisher 2KReviewed on Windows 10, 16GB RAM, GeForce GTX 970Multiplayer YesLink Official site

Just when you think life in XCOM is hard enough, the aliens send super-powered specialists to steal your money, take your soldiers and taunt you while they're doing it. War of the Chosen adds three characterful bosses that harass you in missions and on the campaign map until you manage to hunt them down and hit them at home. You have to deal with them in addition to your normal XCOM 2 duties—contacting new continents, researching the alien threat and beating back the Avatar project. This is a huge, rich expansion, albeit one for experienced commanders already comfortable with XCOM 2's vanilla campaign.