The core of your being has been twisted by an unknown power, granting you the ability to assume the form of the ancient and powerful entity known as the Old One.
When activated, the power engulfs you in an aura of ominous white light, as your body undergoes a dramatic metamorphosis, you assume the divine form of the Old One, towering several stories high. Your body takes on the characteristics of a tree creature, resembling a majestic yet terrifying fusion of ancient wisdom and otherworldly malice. Your limbs elongate and branch out like gnarled roots, and your eyes shine with an otherworldly glow, radiating an aura of absolute dominance.
In this form, you are immortal, and gain unparalleled strength, endurance, and control over the souls of all living beings. Your mere presence radiates a malevolent aura, instilling fear and despair in those who behold you. Your very soul becomes a conduit for the Deep Fog, an otherworldly white fog that can destabilize reality, allowing for the anomalous phenomenon of magic and miracles to manifest in lands shrouded with the fog, while slowly spreading demonic madness across it. You gain intuitive mastery over the magic and miracles of the Deep Fog.
As the embodiment of the Old One, you possess the ability to command and summon demons to do your bidding. These demons can be conjured from myth, resurrected from deceased creatures, or even transformed humans. These demons become your loyal agents, causing havoc and collecting souls for your newfound hunger.