You want the 'Deep' after 'Dark' IMHO.
"Dark, Deep, and Dangerous" Hmmm
"Dark, Deadly, and Dangerous" Redundant.
"Dark, Dirty, and Dangerous" Nah.
"Dark, Drafty, and Dangerous"
"Dark, Discombobulating, and Dangerous"
"Dark, Disestablishmentarianism Dangerous"
"Dark, Drunk, and Disheveled."
"Dark, Doom, and Danger"
EDIT: "Dark, Doomy, and Dangerous"
I also think the slogan should be a bit larger in the banner. The "Dark" starting nearer the 'p' and the "Dangerous" starting after the 'g' might make it more readable.