Zalmarath, The Colossus glitchy one shot (HC experience ruined)

Was having an insane HC run, almost never dropped out of ES for any reason while maintaining 70%+ evasion, 700 hp, 300 ES. 1 tapped by dagger drag.

Can't even tell if its an error on my part because I see other posts of people with tons of hp/armor all getting 1 shot too. Not sure if i should even bother making another HC character not knowing if i'm dying to bug repeatedly or not

bump