first, this post can help you with any build as far as choosing WD% or WD+ if you have limited space and can’t use both. just so you know, WD% increases the DMG of the Weapon including the Item Quality and Power Stat. WD+ is added after. ED% is figured next, and ED+ is added last. also look at the Skill Stats on the Stat Page, especially the Default Skill. there is a mention that if he can find a Horn or another Classes Weapon that can be Jasper to Horn with Legend +200% WD, he would use that instead of a horn with ED%, his DMG would go a lot higher this way, since he uses the Horn for DMG. even though you are going from +300% Ice to +200% Ice, with +200% WD, you are actually going to do more DMG. to give you an idea of the difference in DMG, if your Weapon does 100 DMG, with +300% Ice you are doing 400 DMG, with +200% Ice & +200% WD you would be doing 900 DMG. the math is a little simple, but you get the idea.
if I made any changes to this Build, it looks like changing the Epic WD+ on both weapons to Epic WD% might increase the DMG of the Spells on both Weapons. if not, it is easy to change it back to WD+.
instead of putting Mythic Nova on the OH, put a Master Myth Stone instead, and take off the +5000 Ice on the Helm and put another Master Myth Stone instead. this will increase the chance of Arc to Proc from 30% to 50% a second after it cools down. @cronos4321 was using Arc as his ranged attack to freeze enemies. if you went with the +200% WD on the Horn, don’t put a Master Stone on the Head, find a Head item with +100% Ice (ED) instead. you don’t really need to do this, but if you are ok with 40% Arc instead of 50% Arc, then go for the DMG.
another big change is with Pets. when Patch 3.0 came out, some Crystals can now be used to change affixes on Pets. Calcite (this is the only Crystal that can be used on Eternal Pets), Angelite, Quartz (don’t use this Crystal until you do a Search on it and understand how to use it and why), Diamond, Larimar, Kyanite, Sapphire, Fluorite, & Topaz can be used on Pets. it costs 5 Crystals per use. so if you need 5 attempts to change your Pets Element from Fire to Ice, it will cost you 25 Calcite.
when this Build was made, I don’t think affixes were able to be changed on Pets. if you find any Legend Pets with a Set Affix that would go with this Build, or a Pet with one of the Set Affixes already on the Build, and you want to have another Set Affix on one of the other items, then go for it. if you don’t find a Legend Pet you like, just use an Epic Pet with 6 Epic Affixes.
affixes for an Epic Pet should be +10% Dodge, +15% Freeze (with Legend Elemental Crit, this will make up for not having Nova Mythic), +15% Cool Down (Arc Proc’s more often with a faster CD, and whichever OH Special you are using can be used more often when needed), +20% Ice, +5000 Ice, and the last affix is up to you. if you find a Legend Pet then the last space will be the Set Affix. I didn’t include Deadly Strike because he has 2 Crystal Deadly Strikes that put the Build at the +60% Cap. using an Ice Slime gives a +10% Ice. otherwise, just use whichever Pet you want. just a thought, but the sixth affix on an Epic Pet, or take off the +5000 Ice for a Legend Pet, add +10 Sprint. this will make the Sprint Skill 30, which is a big boost for the Build, since Sprint is the main DMG for the Build.
I don’t see a list of Natures in the Build, but if you have 2 Death Natures, that will get your Crit Chance to the +60% Cap. the other 4 Natures could be Evasion for +6% more Dodge or Elements for +20% more DMG.
I think with the few changes I mentioned, you could still get up into the Billions and I think Trillions DMG.