0. Warning
大法师's going to get nerfed very soon. Although the build doesn't rely on bugged mechanics like the Tempo Choir build, the performance is very likely to go down after the nerf.
The build will still be available unless they completely kill the archmage (it'll work even with 1/3 of the damage the current archmage provides.) 'cause dps is broken now.
It's also an expensive build, keep in mind that you have to spend a lot to make this work, at least 150 div.


1. Build Mechanics

If not considering the cooldown(which is removed by Temporalis), 冰霜之墙has the highst dps among all the spell skills now, even better than Comet, as long as you can break the ice crystals as soon as they spawn. Frost Wall is your main damage source.



-How to play

you manually cast 球状闪电, which is the best skill to apply massive numbers of Shock from its high hitrate and high shock chance.
It triggers Cast on Shock Frost wall and at the same time breaks down the frost walls to do the damage.
Vs Bosses,
--------------------------------------------------------pre-spawn--------------------------------------------------------------------------
1. Cast 球状闪电+ 闪电扭曲 to create a debuff field which applies exposure via support gems.
2. Cast 力量印记
3. Cast 电导率
-------------------------------------------------------post-spawn--------------------------------------------------------------------------
4. Cast Voltaic Mark
5. Cast 冬之眼 for debuff
6. Cast on the boss
6. Drink your mana pot 每 2 次射击产生融化漩涡every 2 shots. Unless you're carrying other people in uber boss fights you don't even need to shot more than twice.

- Archmage
"Gained Damage" from Archmage is always Lightning.
And unlike the common misunderstanding, this added Lightning damage (which occupies more than 90% of your DPS in this build) scales with additive damage for Lightning.
Here's an example.
Let's suppose you have
100% additive damage for cold spells
300% additive damage for lightning Spells
150 Frost Wall damage
500% damage gained as lightning damage (from Archmage)
Frost wall damage per crystal is (150 x 2) + (150 x 4 x 5), not (150 x 2) + (150 x 2 x 5)
So additive cold damage won't significantly impact the performance of this build.

2. Requirements (These are mandatory. Do not start the build until you get all of these)

- 颞肌
This is essential, not only provides utility but removes 冰霜之墙 cooldown.

-220 Max Spirit, most likely you'll be in need of Alpha's Howl (unique Helm), 280 recommended if you're aiming for even better clear.
100 for Archmage, 60 for Blink, 60 for Cast on Shock, and 60 for another Cast on Shock(if you can hit 280, this is not mandatory)

-融化漩涡
You use MoM and mana regeneration will never fulfill the level of sustainability you want.

-High Cast Speed
Unfortunately Cast on dodge is currently bugged and it provides much more energy than it's supposed to.
Since I tried my best to avoid it when i built this, you have to manually cast the spell here.
Gemling doesn't have basic arcane surge so you'll want high cast speed. Get Cast Speed on at least 1 piece of your rings, on amulet, and on your mainhand weapon.
Otherwise you'll get stunned very often before you shoot balls on your enemies when engaged, this is really annoying.

-At least 6k Mana, 8k recommended
You often have to jump into a mob pack. You need tank to survive the time between the jump and your first attack.

-At least 4% Mana on Kill (2 x jewels)
Mana regen is worthless for us.


3. Important Stats

-Skill Level
Our main dps skill is Frost Wall, so you want cold spell skill levels, or Frost Wall levels.
Too high Frost Wall level, however, might cause an issue that actually lowers your dps.
Life of Ice Crystals massively increases as the skill level goes higher and at some point Ball Lightning won't be able to kill the crystals within 1-2 ticks.
And unbroken crystals prevents the crystals from the next cast to be spawned.
So we need more Ball Lightning damage whenever we get more frost wall levels.
Damage of BL's increased by ca. 12% per skill level while Life of Ice Crystals 17~20% per skill level beyond 20level.
You may still use a +3 Frost Wall jewel don't forget to take care of ball lightning level too.
I recommend a wand with "All Spell Skills" instead of "All Cold Spell Skills"

-Intelligence, Mana
They are involved in both tank and damage, just do not miss them on any parts of rare items you equip.

-Cast Speed
Cast Speed is deeply related with your QoL.
Never give it up on your weapon, and get at least 1 on your ring ( I'm running 28% on weap, 25% on amulet, 18% on 1 of my rings. I want cast speed on another ring and am currently farming divs for it. It's really hard to cap res in that case tho)

-Spirit
You need 阿尔法嚎叫 to hit 220, where the build starts to work properly. Otherwise you have to lose a lot of passive points and Ints.
It's the cheapest and the best way to meet the spirit requirement for the build.
If you're interested in the upgrade version I'm running now, you need corrupted Alpha Howl with additional spirit and an amulet with huge spirit.
Feel free to drop the skill level from the amulet for more spirit when aiming for 280, you're strong enough without it and additional 2~3 frost wall levels might cause the issue I mentioned above. Alpha Howl can get up to 130 Spirit when corrupted.
对抗黑暗 is not great as a source of spirit points for our build.

-Increased Area of Effect
This is more important than you can ever imagine. It's involved in four steps of our whole damaging process.
It increases the range of beams from 球状闪电, which means
1. one ball hits more on single target
2. you shock more enemies
3. you break crystals in larger area.
and of course
4. Explosion of Crystals have more AoE size. -> this also helps get more single target dps in light of the wide-spread spawning crystals.
We already have one passive node for it. Roil requires too many points to reach from our passive tree but you can still get it on 自大狂
You can also get a bit more from rare jewels.

-Critical Hit Chance, Critical Bonus Damage

Great to scale our damage even further. Start from the guide-given passive tree and whenever you get more points through leveling, spend them on crit passives.
And get some more from jewels of course.

-Item Rarity
it's already proven that IR above 100% suffers from heavy diminishing returns. Hit 100 and then forget about it. You can get some from Atlas passives and Waystone affixes too.

-Spell Damage, Lightning Damage, Gain Damage

Since we already got high amount of additive / gain damage from Pure Power, Arcane Intensity and Archmage, these are not really worth giving up other more important stats like
Int, Mana, Res, Skill Level, Cast Speed. Just get them only when you don't have to drop something else.

4. Tips for Gearing

- Mainhand Weapon (Wand)
Cast Speed
+3~4 All Spell Skills
Crit Chance
Mana
Spell Damage or Lightning Spell Damage helps of course but they're not on top of our prority.


- Offhand
Mahuxotl's Machination with mana soul core. If you don't have it and replace it with something else,
take Focus or Scepter (Scepter can be a good choice when you run a more budget version) with Mana, Int, spirit(scepter) or cast speed(focus)
Make sure you don't have too high skill level when you chose a focus, we have to tear down the ice walls within 1-2 ticks of Ball Lightning beams.
You may feel a bit squishy if you don't take the unique shield.

-Helm
Alpha's Howl + Soul Core of Zantipi
Get corrupted one with more spirit points if possible. It opens more flexibility when you get your amulet.

-Armor
Temporalis At least -3.00 cooldown for unlimited Frost Wall

-Belt
Ingenuity

-Ring
Breach Ring or Prismatic Ring
Priority is;
1. Mana + Intelligence
2. Resistances (till you cap 75%)

3. Cast Speed
4. All Attributes (also gives us dexterity for Alpha's Howl) or Dexterity
5. Item Rarity
6. Lightning Damage

-Amulet
1. +Mana , Mana %, Intelligence
sadly I had to drop Mana% due to financial issue :/ I spent too much on testing stuffs

2. Spirit (if you aim for 280 setup)

3. Cast Speed
4. Resistances

5. Item Rarity
Passive : Spaghettification, Insightfulness or Mana Blessing


-Boots
1. Mana and Energy Shield (since we run Eldritch Battery, ES = Mana)
2. Intelligence
3. Resistances
4. Movement Speed ( We run Temporalis and Blink!)

-Gloves
1. Mana and Energy Shield
2. Intelligence

3. Resistances
4. Item Rarity

-Jewels
0. 2 x 2% Mana on Kill

1. Meta skills gain x% increased Energy -> hit 100% in combination with Cast on Shock(frostwall) bonus
Our CoS Frost Wall gains 20 per shock on boss and we need 80 energy to trigger it. Excessive Energy is not refunded when overflowed.
Example)
at 99% increased energy gain you get 39.xxx per shock on boss and you need 3 shock procs for 1 frost wall.
at 100% increased energy gain you need 2 shocks.
You need 21% more meta energy when you're running 19lv CoS on gemling. You get a bit more from gemling ascendancy (+gem quality) than other classes.
2. Crit Chances, Crit Bonus damage
3. Increased Area of Effect
4. Magnitude of Shock / Ailments

The priority is very subjective here except for "Mana on Kill"

5. Further Upgrades

- Unique Jewels
Against the Darkness
place it near Repulsion / Reverberation. 1% Mana + 4% Int is the best imo. Spriit if you need a bit more to hit 220/280

Prism of Belief
+2~3 to Frost Wall

From Nothing + Eldritch Battery,
saves us 5 passive points

Megalomaniac
-Mana / Int
Spaghettification Great
Insightfulness Great
Mana Blessing Great

Calibration

-Penetration (This is mostly to counter the waystone mod. In boss fights you have -75% enemy res anyway)
Breath of Lightning

Electric Amplification

Surging Currents

Exposed to the Storm
Flash Storm

-AoE Size
Roil Great
Primal Growth

-Critical

Stormcharged Great

Tainted Strike
Harmonic Generator Great

Barbaric Strength

Cruel Fate

Shredding Force

Deadly Force

Critical Exploit

Critical Overload

Cooked

-ETC
Psychic Fragmentation

Turn the Clock Back

Preservation
Energise


-Second Cast on Shock when you hit 280 spirit
This should help clear larger area.
My recommendation is Detonate Dead + Spell EchoEnergy RetentionImpetus, this simply overwhelms others like Comet in terms of clear.
Remember we already have enough single target dps

I don't like to be bothered ingame and often go afk so please contact me via discord tofumord#6043 if you have a question and want to be answered.