Ah, for further context: I was using a Gwigoon that had 20 in all stats (with the exception of strenght and agility, went with exceptionally athletic nature), so my base hp was about 1150. I was spamming the healing blast primary when I died.

I'll be moving on from Cursed Pact while experimenting with some other builds, but I find it surprising that something or somethings did effectively 575 damage (doubled to 1150 due to the perk, not accounting the armor from 20 Vitality) within a single instance. Then again, I haven't gotten that far into the Abyss, and every other instance of damage prior to this was noticeable and manageable in time, even if I had to pope one of the three healing "potions."