it all looks so good, but I would have to do my own tinkering with a DS build to really help.
I guess the affixes on the Eternal Storm are useful for you, but the Electrified set is not very useful without a Reflect Damage affix.
also, any Elemental affixes, except for Elemental Crit Damage, should be the same as your MH or OH. I don't see your build doing any Poison damage, so your Poison damage on Harlequin's Comfort is wasted, and so is the Blight on Diane's Love. it only works on Poison Cloud. and the Fire damage on Gowther's Insight. I would change the Poison and Fire % damage to Shock, to boost your Sword, and the Blight to Frostbiting, so when your Horn Freezes anything, anything that damages a Frozen target does extra damage. but you would need some Elemental Crit Chance for that to happen, or replace that with something else. or change it to High Voltage, so any time you Stun something with Shock Elemental Crit Chance, they also cause extra damage, like Frostbiting.. these changes only need Calcite, except for getting Elment Crit Chance. Angelite for 15% of a specific Element Crit Chance, or a Ruby for 30% any Element Crit Chance. the Ruby might be better, as it would give 39% Elemental Crit Chance for Shock and Frost at the same time, with the DS 30% boost to % based affixes.
umm, I hope this helps.