Level 44 Hybrid Crit Ice Nova of Frostbolts Occultist^3.24

Notes

NOTE:
All of the rare gear in this build is just an example. You do NOT need to get rare gear exactly like mine, or even close to it. 
These are example stats of what you want. Most armour gear will want some combination of life, resistances, and other defences (hopefully mostly ES and armour, but socket colors and links are more important early). This is for the purpose of increasing your max hits as seen on the left in PoB
Recovery is also important, though early on that will mostly be handled by flasks, thus you don't see much in the passive tree or on my gear for recovery. That is reserved for the endgame when you swap out life/mana flasks


CAMPAIGN:
ACT 1:
Can use Spark or Freezing Pulse early. Spark is better for killing Brutus
Look for 2b1g wand or 2b1g shield
Grab frostblink and clarity 
freezing pulse - added cold damage - arcane surge is generally what I use for early links
Swap to Ice Nova after fairgraves
Don't worry about leveling up frostbolt at this point. Level 1 frostbolt is what you want until you no longer have mana issues
Also, keep a live search going for ice nova of frostbolts. If you get an early chaos orb or get a good transfigured gem you can sell or swap for it, it's definitely worth it
Can ask a duelist/marauder/templar friend for shield charge. This will speed up the acts a lot
Can ask anyone who isnt a witch for faster attacks in act 2 for shield charge (discrimination is real)

ACT 2:
Grab herald of ice
Swap arcane surge for faster casting towards the end of act 2 
Grab another faster casting for frostbolt if you're going to use frostbolt before you swap to spell echo on ice nova
Grab Crit Damage support, Crit Strikes support and Power Charge on Crit support and start leveling them for later 

ACT 3:
Grab Zealotry and start leveling it. You can decide whether or not you want to turn the aura on. It can cause some mana problems early
At the end of act 3, ask a shadow or ranger friend for either Slower Proj or Returning Proj. Not required, but helps 
Look for a 4b or 3b1g piece of gear for Ice nova
Trade for Ice Nova of Frostbolts asap 

Optimal 4 socket Ice Nova at this point is Ice Nova > Faster Casting > Increased Critical Strikes > Increased Critical Damage
Can also do Ice Nova > Added Cold > Faster Casting > Increased Critical Strikes
Can also do Ice Nova > Faster Casting > Increased Critical Strikes > Power Charge on Critical, and then take power charge notables/ascendancy early

If you get a 2nd 4 link, can do Frost Bolt > Faster Casting > Returning Proj (or Slower Proj) > Volley. Otherwise, drop Faster Casting
Can also do a 4 link with Frostblink. It's surprisingly effective through the campaign and early maps on trash mobs with Herald of Ice. Would recommend doing this if you're having trouble getting Ice Nova of Frostbolts
Frostblink > Increased Critical Strikes > Increased Critical Damage > Added Cold Damage
    
ACT 4: 
Grab bonechill support and link it to frostbomb or frostblink. You'll want to hit tankier mobs with whatever skill is linked with bonechill first, and then beat em up with ice nova
grab spell echo and lightning golem
Get spell echo before fighting malachi. It'll make the boss fight many times easier

ACT 5:
Grab the mana reservation mana mastery. Should be able to turn on hatred sometime between now and the end of act 6 and sustain mana

ACT 6:
Grab these gems Lilly's quest and start leveling them. Don't need to use them yet. Priority for leveling is in order:
Inspiration
Tempest Shield
Petrified Blood
Defiance Banner
Arrogance
Flame Dash

Grab these gems if you didn't get them earlier:
Ice Bite 
Shield Charge
Faster attacks (link with shield charge)

Start working on gem links and aura set ups over the next few acts:

Ice Nova of Frostbolts > Spell Echo > Inspiration > Increased Critical Strikes > Increased Critical Damage (or Power Charge on Crit)
Once you start getting close to 100% crit chance, you can drop the chance to freeze nodes on the tree to free up quite a few passive points, as cold damage crits have 100% chance to freeze

Frost Bolt > Faster Casting > Volley > Returning Proj (or slower proj)

Steel Skin > CWDT > Increased Duration (if a socket is available) 

Shield Charge > Faster Attacks

Arcanist Brand > Frostbite >  Frost Bomb > Bonechill

These don't need to be linked:
Herald of Ice (can be swapped out for Arctic Armour or Tempest Shield)
Zealotry (can be swapped out for clarity)
Defiance Banner ( can also be swapped out for a low level clarity)
Flame Dash

If you have extra sockets, can throw these in until you can swap to low life:
Frost Shield
Sigil of Power
Automation (for the above)
Portal

/CAMPAIGN

EARLY MAPS:
Good wand with either + to all gems or cold skill gems, cast speed, crit chance, spell damage, etc. for leaguestart. Threw an example in the early maps items. This just lists some valuable affixes, getting all will be hard and expensive, and you would be better getting something that's good enough
If you're slow or it's after league start, then tulborn or tulfall or voide battery are good options
Reverberation rod is also a good, cheap option and can be used in the acts starting around act 3
Mark of Submission with Frostbite is a huge, cheap QoL change once you do 4th lab and get Profane Bloom. Can upgrade to another curse on hit ring later, or surgebinders with ele weakness on hit corrupt

Grab Eldritch Battery so you can ditch the mana flask. At some point, you'll get your mana costs reduced enough that you can ditch EB
Can grab some spell leeched as ES if needed to sustain 
Can turn on 2 big auras and herald of ice once you get the mana mastery for reservation, the reservation efficiency node on the top right on the tree, and 6% RMR from an essence craft on your helm or chest

Cap resistances and get needed attributes
Fill out life/es nodes on passive tree
Swap to at least a 5 link ice nova
Tulborn (void battery or Tulfall if available are better) + malachai's loop + ralakesh boots + badge of the brotherhood is the early end-game goal for uniques. Once you have these, you should be able to finish your Atlas and get your voidstones
Get needed flasks

LATE MAPS:
Work toward mana reservation efficiency nodes so you can turn on a 3rd aura (can use either hatred OR haste. I have both in the PoB, one is disabled. Hatred is slightly more dps, but less zoom. Haste has more mana issues) 
Swap to a 6 link ice nova
Swap in the 4 unique setup (Ralakesh boots, Malachai's loop, Badge of the Brotherhood, Tulborn or Void battery)
Swap out Herald of Ice for Tempest Shield for shock immunity for Malachai's Loop
Work on survivability for rings, belt, gloves, and helm in preparation for swapping to low life
You don't need an enlighten for the beginning late-game low life version of the build, but you'll need one eventually, as most late-game builds do
Once you have at least 4k health (can use Utula's chest to get there pretty quick)  you can swap to low life


UPGRADE PRIORITIES THROUGHOUT MAPS IN ORDER:
Cap Resistances (if not capped already)
Good weapon (tulborn, divinarius, tulfall, or +1 wand with spell damage, cast speed, etc). Can even use a staff if desired, at least until you start using malachai's loop
Flasks
Swap to a 6l Ice Nova of Frostbolts
Attributes
Badge of the Brotherhood
Ralakesh Boots
Malachai's loop
Quality on gems
Swap to low life


(MOSTLY) FULL ATLAS/ENDGAME: 
Decide how far you want to take the 4 unique combo. Can stick with it or swap to a Farrul's fur setup and drop the endurance charges. It's less tanky, but much faster. There are numerous ways to build around Ice Nova, but this is the simplest one
Decide which high-ticket item you want to obtain first. I usually go for a +1 power charge ring before mageblood, as they rise in price extremely fast over the first week or two of the league
This build is a good all-rounder build, and excels in most content. You may need to make a few changes in the passive tree or swap out some gems for different content, but that's easy to do. 
This build really excels in blight-ravaged maps, simulacrum (need higher budget to do wave 25+), logbooks, breachstones, and bossing. You can make a few changes to make it a speedy mapper as well. 

Breakpoints: 
Act 3 - try to get ice nova of frostbolts

Act 4 - spell echo. You'll want to be running a fairly high level clarity at this point and have mana regen nodes allocated. This is only if you got an early ice nova of frostbolts

3rd lab - You'll want to have the charge mastery cluster and both + to max power charge nodes taken by this point 

around this point you should have enough crit chance to drop chance to freeze

6 link ice nova - ice nova will get so expensive that your mana won't be able to cover it. Either get a mana flask with reduced recovery rate so you only need to drink it every 10 seconds or so, or drop clarity and start using EB. 

6% rmr from gear, 8% from node, and 12% from master - can use HOI and 2 major auras. Would recommend Zealotry + hatred, zealotry + haste, or zealotry + determination

Once you get a decent 6 link, decent flask setup, and a good wand, you can do t16 maps. It'll be difficult still since you'll be squishy, but you can do them

around 4k life or when you get utula's working you can swap to low life


Cheap uniques to keep an eye out for that are helpful for early maps or campaign:
Tulborn (breach boss only drop, so not likely to see day 1 of leaguestart) 
Light of Lunaris
Zeel's Amplifier
Reverberation Rod

Uniques to keep an eye out for once you get to maps: 
Void Battery
Tulfall
Malachai's Loop
Ralakesh boots
Badge of Brotherhood
Tulborn
Divinarius
Utula's Hunger
Willclash
Surgebinders