This character, which 3D Artist SnakeH describes as a big challenge, has been in progress since last May, with Substance 3D Modeler used to create most of the design in VR, followed by refining the details in ZBrush.
SnakeH has also revealed that the gun was created using Plasticity, and the face of this character is based on their friend. Take a look at the WIPs shared by the artist and appreciate the meticulous work that went into this project: