Plague Doctor Trait Damage

I am tinkering with a stat drain/stat buff build around primarily Death spells like Terror and creatures that steal stats on attack/decrease stats per turn. However, Plague Alchemist doesn’t seem to work right.

Plague Alchemist does seem to be doing damage when stats are drained, but it’s certainly not 50% of the drained amount. I drained a total of 120 stats and I believe they took somewhere in the neighborhood of 15 damage. I’m also fairly sure not all reductions trigger it properly; for instance, Spitting Pit Worm’s defense shred seems to only cause 25% damage, and Delirious Ghoul’s 40% Speed steal is also fractional of what I expect. In my testing, almost every drain was between 1-3 (Assuming Drain X indicates the damage, which correlated to the HP bar)

I was under the impression that this damage was not resisted by defense. If it is, then Plague Doctor is entirely useless, as there’s no chance for it to drain enough to bypass even weak creatures. Plague Doctor’s damage also seems affected by classes, doing more or less, which is less of a big deal to me. I think flat percentage reductions should work on it, but not defense.

Windows Steam, 0.1.9