Originally Posted by
Yugl
Update: Impact's effect is Dark Resist Element.
Sawtelle noticed a 10s duration for two casts, so I looked into that. If you correct for ~2s and look at the ES Impact picture, the 10s durations are really 11.25s and the ES Impact's duration is really 90s. I went out and retested the ES Impact and found 90s duration again. Thus, the effect is unresisted like Bio/Dia, but the duration can be resisted. The duration resistance is Dark Element. New images added to the previous post's link.
Edit: Sawtelle points out that the damage indicates duration resistance; thus, if you do half damage, expect half duration. This could be an interesting tool for future tests....