Ohh, I see what you mean. They switch prayers at 3100, and there was a delay between hits which negated the second hit.

 

My apologies. I'm an idiot :p

Small update: darklight is super overpowed after Dimension of Disaster. You can hit more with melee without the demon switching its prayer (how much more, no idea, probably 2.5x more) and the accuracy/damage is insane.

 

So best setup would be something like melee + mage with Steel Titan. With mage gear/ability bar, toss holy water, force the demon to mage prayer, annihilate with melee, finish with mage.

 

Side note: destroy's next hit will always go through even if it would have triggered a prayer switch from earlier damage. Or is that assault? One of them at least, maybe both.

 

I wouldn't be surprised if with some refinement 190+ kph is possible now with just melee/magic. At least 170 or 180.

 

edit: darklight nerfed on demons, ignore.