Admirals, I present to you the future of space warfare! No longer will you need to waste billions of credits on costly space battles, and millions of lives on planetary warfare with hostile cultures. For only a fraction of the cost of a heavy cruiser, I present you with a weapon capable of eliminating an entire solar system. "I present the Star Hammer!"
(A powerful and deviously simple weapon to make space warfare in any sci-fi game forever changed)
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.