Shape-Shifting - The Doppelganger can change his form and gender at will. He transformed into Jenny at one point. He can also imitate clothing. He can also adopt monstrous features such as claws, large fangs, and some Darkness armor.
Voice Mimicry - The Doppelganger can imitate the voices of others.
Super Strength - The Doppelganger can easily overpower and eviscerate humans with his bare hands.
Teleportation - The Doppelganger can travel to any location instantaneously without occupying the space in-between. He achieves this by walking through portals through the shadows.
Telepathy - He can hear the telepathic voices of the Darklings and the victims of The Darkness.
Conversion - With a single touch, The Doppelganger can turn a person into a Darkness creature bound to his will.