Depth of Extinction

The Butcher is not a character class you can pick from the start. Rather, you have to complete the Butcher mini-campaign of a few missions in 3 areas. Once you complete that, you have access to the Butcher . Unlock this achievement by choosing the Butcher option when a recruit is ready to level up for the first time and you have to pick a class for the character and you have completed the mini-campaign.