Since we're on a ridiculous rant atm, how about~:

Insatiable Thirst
Casting time: Instant
Recast time: 2hours
Duration: 1min
Effect: For as long as Insatiable Thirst is in effect, every second whatever the Dark Knight is engaged with has it's HP drained with an uncapped formula. Also, each attack the Dark Knight lands on their target(Physical or magical) drains an additional amount(also includes Weaponskills and it DOES DAMAGE; unlike BW). Lastly, any form of damage the Dark Knight receives drains that much from wherever the source of that damage came from.

Yes I know, completely ridiculous, but I find it necessary haha.

P.S.: This is what DRK's 2hr should have been in the first place imo.