Here is the full list of all 27 The Devil Within: Satgat achievements.
Find all of the Haetae in the Abandoned Wasteland.
Find all of the Haetae in the Dark Forest.
Find all of the Haetae in the Ruined City.
Defeat Mother Gaia to foil her plans in the Abandoned Land.
Avoid the bombardment and get to safety in the Abandoned Land.
Obtain the gun, 'Red Panther.'
Escape the chamber and activate the ventilation in the Abandoned Land.
Destroy all of the tanks in the Abandoned Land.
Use the excavator to get across in the Abandoned Land.
Open the door of the dam in the Abandoned Land.
Enter the Abandoned Land.
Strengthen any Sword or Gun to at least +5.
Defeat the Devilized Lee Choong in the Dark Forest.
Defeat the Black Crow Enforcer in the Dark Forest.
Defeat the Black Crow Assault in the Dark Forest.
Defeat the Black Crow Scout in the Dark Forest.
Reunite with the woman investigating the Black Crows in the Dark Forest.
Enter the Dark Forest.
Arrive at Mirabeol and learn more about the situation.
Unleash the power of the devil upon Lee Choong in the Ruined City.
Avoid the giant worms and get to safety in the Ruined City.
Use the power of the Ritual Bell' artifact, Soul Destruction, in the Ruined City.
Obtain the 'Ritual Bell' artifact in the Ruined City.
Obtain the gun, 'Wanderer', in the Ruined City.
Take down the leader of the Wetas in the Ruined City.
Head covered now head forth!
Begin your journey at the Ebon Sting.