The War of the Chosen Add-on for XCOM 2 has 10 achievements worth 170 gamerscore.
Complete the Lost and Abandoned mission
Permanently defeat one of the Chosen
Get 15 Headshots against Lost in a single turn
Get four kills from Shadow mode with a Reaper in a single mission
Raise a Templar to maximum Focus level, spend it all, and reach the max again in a single mission
Perform three offensive actions against the same target with a Skirmisher in a single turn
Form a level 3 bond between two soldiers
Complete a mission with all Tired soldiers and no casualties
Raise XCOM's influence with all three factions to High in a single game
Rescue a soldier who was captured by the Chosen