That isn't very dark.

They could be 'The Daggers of Megiddo' (+ 2) A series of seven consecrated daggers that could kill the Antichrist ! (From the film Omen) .... Dark enough for you ? :~)

There's 9 knives

That's why I said (+2) :~)

Oh

Knives cannot (in themselves) be dark; only their user.

Fair point ... but those knives are the only defense against the 'evil' one - The stabber /user doesn't matter :~)

Defense is not dark, it's glorious. (make sure to roll the "r" in "glorious")

You're Rrrrrrrrrrrrrrrrrrright ! :~)