Thanks for the feedback. That would be the flat damage bonus of Lethal assault applying twice, correct? Percentages wouldn’t double. But the flat damage is pretty huge.
Dual wield does however allow you to put in two cold stones for +200% cold damage, so that is another big advantage. (Took me an embarrassingly long time to realise you could do that. With my sorcerer character I just assumed that you could only have 1 instance of a buff active and never thought to test it.)
Soulrend comes with cooldown and a Nidalla’s Justifiable Ends boost, so it gets cooldown down to 1.4 seconds which I think is pretty good. With Spectrals I get 1.5, spectral and loxmere 1.3. (But the loxmere I got is a weak version.) And the lifesteal is insane. 25% total. (Thinking of dropping Ghoul since it seems a bit redundant with that much life-steal going on.) I get a feeling I got extremely lucky finding it the first time I ever stepped in legendary Steps of Torment.
Did find this Shadow Strike build by @banana_peel that uses Winter King: [1.1.6.2] Endless Winter. Bane of the Winter King family: SS Infiltrator, CT Spellbreaker, pseudo-pets Trickster, PS Trickster, BA Blademaster
But from looking at patch notes I think that was from a time when that sword gave cooldown reduction.