itsme wrote:AFAIK it's the same deal as Curare. It's a passive damage source, which means it gets multiplied by the WDM on the skill (and also spell damage if direct melee). Physical weapon damage (ED/EWD/whatever) doesn't affect anything. The Pounce nova is WDM but not direct, so it carries the effect but lowers the damage to 60%, and isn't improved by spell damage.
It's true EWD doesn't affect flat Elemental damage, but I'm pretty sure skill WDM doesn't affect it either. For example, neither Enfilade's flat Cold damage, nor Hammer of Zerae's flat Lightning damage seem to be affected by either skills' WDMs (this is based on LCS numbers, so who knows?). I say Curare is different because the skill description specifically states: "The Elemental damage from this skill is affected by weapon damage multipliers on attack skills."
Edit:
Looks like it may be different for flat Elemental damage from skills vs. from items. Just checked with Toorc's Gift and that Cold damage is indeed affected by WDM, whereas Enfilade's is not.