Interesting. Here are my thoughts. With the change to cold mastery now meaning its at 1/5 vs sundered immunes, I've seen the idea of using a 1h Doom for the high reduction to enemy cold resistance similar to a self-wield infinity nova sorc. At first I just dismissed it because obviously Fathom is GG and cold mastery means capped negative res for most mobs, but looking at my current cold sorc (which is a Blizz-Orb build) and running some numbers, it actually seems to have some decent potential - some numbers below to illustrate the idea, curious if anyone's done any extensive playtests or similar and how they found it. Skills (at lvl 94) - 20 blizz, 20 FO, 20 CM, 20 ice bolt, 1pt wonders, remaining 19 ice blast. Core Gear - 20/5 Nightwing, Spirit, Arachs, Trangs, 2/10 ammy, 2SoJ. Charms torch, anni, sunder, 6 skillers, gheeds. Swap Gear (both hit 105fcr) - S1: Fathom + Enigma / CoH - S2: Doom + Vipermagi. (Unfortunately I don't have a blizzard Ormus to test with! But given that either weapon would use it for absolutely maxing damage, it can be discounted as a roughly consistent factor across the two. Also, with zero res on the weapon OR the armour your overall resists can suffer noticeably, so I'll stick with Vipermagi for the comparison). The Death's Fathom is a mediocre roll (+28 with facet) and the vipermagi is unsocketed, so both have ~5% additional cold damage as potential room for improvement so the comparison is fair. S1 sheet damage is 9301-9630 Blizz, 1309-1365 FO. Average 9465 and 1337. S2 sheet damage is 7073-7333 Blizz, 1011-1055 FO. Average 7253 & 1033. Conclusion 1 - against non immunes, who are already at the negative res cap without needing the minus res from Doom, Fathom setup hits approx 31% harder thanks to the +2 additional skills and the %cold damage on Fathom. No surprises there! Immunes, though, are where things change... S1 enemy cold res: Sundered to 95, then -48(lvl 45 cold mastery), -17 (infinity merc), -10 (2x facet). Enemy res = 20. Actual damage output = Sheet damage * 80% ~ 7600 & 1050. S2 enemy cold res: Sundered to 95, then -46 (lvl 43 cold mastery), - 17 (infinity merc), -5 (1x facet), -40-60(Doom). Enemy res = negative 33 - negative 13. Actual damage output = sheet damage *1.13-1.33 ~ 8200-9700 & 1150-1400 (varies with Doom roll, if Vipermagi were faceted that's a additional 5% off enemy res which would add another ~4% effective damage output). Conclusion 2 - against sundered immunes, a well-rolled Doom with Vipermagi hits up to ~35-40% harder than a Fathom with Enigma / CoH. Given that immune mobs are the ones that will slow you down the most, it seems there's a pretty solid case for using Doom if farming an area that's dense in cold immunes such as Chaos. Noticeable damage is lost against non-immunes but they die very quickly regardless, so losing a chunk of damage against them to dramatically improve kill speed vs the common immunes that actually slow the run down could end up being worth it overall. Obviously somewhere like Cows it's still Fathom with no competition at all. I was going to do further comparisons for options such as a 6-facet sword for +30CD and -30 enemy res (at the cost of +skills), or a 4 facet shield in place of Spirit, but firstly - I don't have any of those so it would all be estimates and secondly - this shit is getting long enough already! Has anyone tested a Doom cold sorc out and done timed runs on high player counts or anything, see how it feels? Interested to hear thoughts from anyone else who has had a real look into this, or any other setups you've found success with