The Definitive Dark Knight Guide

[Xenosan]

my lvl56 Opener for solo/OT (bolded is GCD, ital is oGCD)

Dark Arts > Blood Weapon > Plunge > Scourge > Low Blow > Dark Passenger > Hard Slash > Dark Dance > Salted Earth > Syphon Blade > Dark Arts > Souleater ****Reprisal as soon as it procs wherever within this duration, since Dark Dance buff is up, it will likely proc****

^If Reprisal proc'd and used before Blood Weapon falloff, you will be almost right back to full MP before second Dark Arts. I'd consider even opening with Dark Dance. The earlier it's up the sooner Reprisal procs. The problem though is can't put it in front of Dark Passenger or else it'll consume Dark Arts for lolevasion.

I haven't reached Carve and Split yet, can't wait to start testing it.

My MT opener is relatively similar - Blood Price instead of Blood Weapon, and depending on the engagement the rest of the rotation changes. More mobs means more Abyssal Drain / Dark Arts > Dark Passenger, Unleashed, etc. But if only 3 or less it's usually rotating Scourge and the occassional Dark Passenger / Abyssal Drain (depends on Blood Price returns).

For single target the above rotation is used, follow Souleater with Power Slash combo. I haven't decided yet whether Dark Arts > Power Slash is justified. That's 3 Dark Arts by only 1 Syphon. From my testing Dark Arts cost ~26% of base MP each, Syphon rewards ~13%. (2 Syphons == 1 Dark Arts). Blood Weapon is 3.5% of base MP returned for each attack, including AAs (Mercy Stroke counts as physical too). Blood Price yields 5.5% per hit. More testing required, but so far as I can tell, MP returns are based strictly or lvl/base stats. Stats don't change returns, neither does the amount of damage inflicted increase Blood Weapon returns, nor does receiving higher damage increase Blood Price returns.

There have been a few times where I've been shocked to see my MP recover whilst in blood price, will keep an eye for whenever that happens. Might be some secret

Openers

UNMEND > plunge > HARD SLASH > blood price > SPINNING SLASH > dark arts > POWER SLASH > salted earth > SCOURGE

I would recommend opening with Dark Arts, it has a 10 second duration so it'll last just long enough to reach Power Slash (though it may be safer to throw Dark Passenger or C&S in and use a second DA for Power Slash), native MP regen + Blood Price will be maxing MP regens.

Blood Price may be over-healing your MP pool since you haven't consumed much mp yet save for unmend (which again is why i recommend opening with Arts), that is potential waste. And frankly I don't think unmend is necessary at all. Even though it's the cheaper of our MP abilities, it's still a waste of MP that could be elsewhere in Dark Arts or better MP consuming WSs.

I only really bother with Dark Arts > Power Slash for boss fights, but it's usually after my aforementioned opener. (So 3rd Dark Arts goes to Power Slash. Recap: first > Dark Passenger, second > Souleater, third power slash). Hate has never been a problem for me even with starting with Syphon combo.

note: 2 oGCDs between GCDs is boss