Hellblade: Senua's Sacrifice

This achievement is story-related and cannot be missed.

Once you have arrived in Helheim, you will soon learn of Fenrir, a horrifying monstrosity that attacks from the shadows. This chapter is very intense because you will experience intense trauma and die if you stay in the darkness for too long during your travels. As such, make use of your torch, beams of light, and fire braziers whenever you can to stay alive. Eventually, after passing through three sets of puzzle doors, you will reach Fenrir's lair for a battle. The achievement will unlock after defeating him.