“Wind of Death” weapon negative enchantment states, “Lose 5% Health on Damage Dealt.” When I have a barrier, the damage dealt is taking from my barrier, not my health.
The damage needs to either take from my health, as it states, or the text needs to change to “Take damage equal to 5% of Health on damage dealt”
so if you went down to 0 hp with Wind of Death and still had your barrier up what would happen then? 
Probably still kill you like usual, though there is a “bug” currently that makes Wind of Death not kill you if you have any lifesteal even though the healed health from lifesteal isn’t larger than the damage from Wind of Death