Illustration of an epic dark fantasy realm, featuring a cartoon-inspired yet realistic depiction of mystical landscapes shrouded in shadow. Soothing tones of deep blues and purples blend seamlessly with rich blacks and hints of fiery reds, reminiscent of a Diablo 4 atmosphere. Imagine majestic castles perched atop jagged cliffs, ominous skies swirling with storm clouds, and mysterious creatures lurking in the shadows, creating an immersive and captivating wallpaper.