https://pobb.in/rllhe29gnBR4

i cannot in good conscience recommend this build to anyone as-is. i chose raider to go marginally faster than the alternatives. for an all-rounder build, i would recommend ascendant going raider/elementalist and probably slayer on forbidden jewels for overleech. a more sane builder would drop the proj/duration scaling from the tree, use a different lightning skill, and reinvest in a more respectable life %. i would also recommend getting proper ailment immunity instead of 75% reduced effect of shock and immune to freeze and saying "eh, good enough".

key interactions:

• omniscience gives us 218 ele pen and all res, fueled by jewelry corruptions, black sun crest, and ~130 flat attributes on each of our rares
• melding of the flesh + 23 purity of ice + a 3% megalomaniac + body armour influence gets us to 90/90/90 res (megalo can be dropped with elevated max cold res on body and gloves but it's a pain to roll and means dropping unnerve)
• converting 96% of lightning to cold gives us up to 1176% increased damage with perfect rolled nebulis...es. swapping in annihilating light with no other changes represents 45% less dps (of course you would pick up more increased damage if you went that route, but that's still a hefty difference)
• with all that increased damage and ele pen, our main scaling factors are cast speed, flat damage, and crit. duration, # of projectiles, and proj speed give us better clear, with the first 2 also providing more dps from multihits on bosses especially in small arenas
• transcendence herald of ice MTX provides negligible damage and clear but looks really pretty
• evasion cap (with a better body armour or vaal grace up) and 100% spell suppression lets us play much more recklessly than 3500 life would suggest. the build does still have softcore moments, particularly against ele pen and phys/chaos degens

pob link above includes recommended budget substitutes for my turbo-luxury gear (string of servitude for mageblood, transcendent flesh for triple multi life jewel, conq efficiency + replica for tailwind forbidden flame/flesh). to match a 10-20ex budget, you'd additionally need to:

• fix flasks & mana (drop enlightens, herald of ice, determination, bottled faith. add purity of elements)
• drop jewelry corruptions and helm enchant (a rare helm would probably be better if you're using string of servitude but i can't be fucked to math it out)
• drop alt qual and awakened gems
• swap tornado for cold snap since testing indicates it's not applying a substantial chill for bonechill and the 20 proj limit sucks for spark (even if it is theoretically an additional 5+million dps on single target)
• get maim immune on a jewel, swap garukhan to yugul, and add a source of consecrated ground for 80% reduced effect of curses
• cut the bonus dex from the custom modifiers in the pob in half, since that's coming from my extremely good Brutal Restraint (there's another 5% on Flash Freeze, too)
• swap bandit to alira

this should give you enough ele res to make up for a lower omniscience total and round off some of the other edges without gutting the core of the build.

how to craft decent double t1 attribute rares:

• buy the base uninfluenced (you can buy it with the implicits you want like i did with the body armour, but that means it needs to be exarch dominant and you can't fix suffixes later)
• slap them with deafening attribute essences (check your bases on poedb and use essences that can't roll naturally on the item) until you get double T1 attributes (chaos res also acceptable)
• lesser eldritch ichor + eldritch annul if you need to remove an unnecessary suffix, repeat 2 if you annul the attributes
• craft trash prefixes if any are empty, greater eldritch ember + eldritch chaos/annul/exalt until you get passable prefixes

the build is hardly complete - there are a number of optimizations i'd still like to make, but with elden ring launching in a few hours and 38 challenges done, i probably won't be revisiting it this league. i just wanted to share the culmination of my experimentation with omniscience & one of the most fun mapping builds i've ever played.