Ah, yes. The darkest of nights and the reflection of a casting light. In Shadow lies the powers of stealth and silence, the ultimate tool for a secretive victory.
Completely silent; jumping from Shadow to Shadow, he stalked his prey through the streets. Dawn would be coming soon, and he did not want to be caught within the enemy’s grasp.
If you want to add a "supernatural" touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.