[1.6] 1600 damage torque?

[scul]

So just died on my cursed that was fairly well equipped. Playing nightmare with no game altering mods (a few to add classes, but none that add random items). At almost full health I blindsided a normal cultist. Not a boss or rare. He was able to use acid wave rune, then cast grace of eternals, then cast drain, THEN use a torque that did 1600 damage after resistances. I have decent (for my level I think) physical and all resist. He had less than 200% crit multiplier, 20% phys damage boost and only 9% phys damage penetration, I had no debuffs that should enhance the damage I take. That just seems like too much for a non rare, non boss that is not near end game to be doing. Also I am not sure how he was able to get 2 abilities off that should take time when I was not slowed and he was only at 150% speed(only after casting grace of the eternals and already taking a turn to cast acid wave). Unless the torque is instant cast, which would be even more broken.

https://postimg.cc/CnxmNR2p
https://postimg.cc/GBnKf7fQ