The Soul of the Rotted Greatwood is a pulsating, luminescent orb with a sickly green hue, emanating a faint, eerie glow. Its surface is semi-translucent, revealing swirling dark veins within, reminiscent of decaying wood and corruption. The orb is encased in a fragile, bark-like shell with intricate, gnarled patterns that suggest its origin from the cursed Greatwood.