[1.6.4] Disruption shield causes unexpected damage

[qweasd]

Deadly poison from a white thief in maze hit me for over 600 damage, even though the tooltip shows 80 damage per turn.
In another case, a 400 blight spit hit me for 900 damage even though the enemy has 150% crit multiplier.
Both cases happened when the damage instance broke the disruption shield.
People on discord have suggested that "mana drain was added on top of the damage" as a possible cause of this bug.