King of the Mist one hit invisible attack

It's second time in a row in which I got hit by some invisible attack during second stage of fight.
First there is clear chaos explosion visible, then chaos bulbs appear but not explode.
Would say skill/build issue but with 32% chaos res and 1955hp plus 20k evasion rating it literally one shots me and I dont even know what is it, as literally there is nothing happening on the screen.

It only does chaos explosion, one hits, after that some purple bulbs appear from which I guess explosion should come.
Unfortunately explosion happens first and bulbs appear after.