Here is the full list of all 18 Hollowed achievements.
A life after death
Meeting the god
Sinking deep
Expressing aggression
Learning the motivation
Roaming the gods realm
Making a trade
Avoiding the seeking hands
Rejecting Life
Choosing Oco
Saving Inna
Ringing the Bells
Surviving the Collapse
Running from the past
Scaling the world
Seeing the future
Moving forward decisively
Creating a relationship