They're powerful, they have unique abilities, and they can make missions in their region tougher until you devote the time to take them out. The Chosen function similarly to the mini-bosses seen in XCOM2's DLC: There are three of them, and they'll show up to mess up your missions. This includes things like timed missions or masses of enemies or even the titular Chosen.

The Lost don't appear in the game that often, but they're used as part of War of the Chosen's toolbox to mix missions up, appearing as a part of the SitRep system which throws a spanner into certain situations to keep things interesting. But fighting them presents a unique challenge where the enemies are trying to overwhelm you with sheer numbers, and the biggest threat is having to reload at an inopportune moment. The Lost aren't a real threat, they're just a complication, attacking both your XCOM troopers and the alien menace alike. The Lost often have just a few hit points, and they move towards you slowly and predictably, hordes clawing out of the earth in response to explosives. The Lost are a call back to the green gunk released in the opening of XCOM's tutorial mission, but let's call it what it is: The Lost are zombies, exploding out of buildings to charge at you. While the many changes do a lot to make the game more complex, less forgiving, and much more demanding of players, it accomplishes this in an elegant way. It's overwhelming, but once I settled into it I found the game was deeply rewarding and filled with nuance and strategic options. War of the Chosen doubles down on this, with angry pop-ups telling you how important your assistance is in pretty much every region on the globe. XCOM 2's tactical overmap was always a bit much, a wall of noise that drags you this way and that around the map as you desperately try to keep a collection of antique plates spinning to save the human race. Soon after that, though, everything comes apart. The game starts with four rookies blowing up a monument to show the Advent administration what time it is. The brilliance of the expansion pack for the game - you'll need the base game by the way - doesn't become apparent immediately. I've sketched out turns in the office, tried to explain situations to my partner as I eat, tried to work out impossible battles in the shower. I've played it for hours every day, and when I'm not playing it I'm thinking about it, turning over tough turns in my head. I'm not sure when it happened, but XCOM 2: War of the Chosen has spent the last week insidiously taking over my life.

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