A Drk or a Hero Post-BB?

Beholder's Revenge falls into the Single-target lot, not mobbing.

Another slight disadvantage for Sacrifice is it being a single-hit skill, like the old Blast. While not many people should see this problem, it remains to be a problem.

With that in mind, the number is:
690%*160%*(60000/660) + 700%*60/5 = 108763.63% DPM
For Drk.
I haven't confirmed, but from what I can recall, Beholder Revenge does not trigger critical damage. So if you're going to plug Crit in, keep that in mind.

Personally, I don't think Drk is anywhere close to Hero in terms of 1v1 damage.

Brave Slash, Advanced Combo Attack and Enrage all can be raised by 2 levels with Combat Orders; for Drk, only Berserk can. (Although I just learned that lvl 32 Advanced Combo doesn't do anything, lulz)
That's a difference of:
Hero: From 200%*210%*160% = 672% to 200%*214%*164% = 701.92%, a 4.45% damage increase
Drk: From 160% to 162%, 1.25% damage increase.
Supposing Advanced Combo adds 10% dmg every orb, multiply by 10 orbs. I have no idea how Heroes work.

And I'm going to say it now, the only defense being PDRate has nothing to do with Sacrifice having to ignore it. Unless you have proven it somewhere, make it known or post it here.
Nevermind, it does indeed ignore monster's defense, most likely PDRate.