Level 96 Hybrid Crit Pyroclast Mine Saboteur^3.21

Notes

Link to YouTube Video: https://youtu.be/NSU5BFzyFMM

---------Act 1----------
We start the way all mine builds start: stormblast mine.
Your first links can be arcane surge and swift assembly.
I'm inclined to slightly distrust arcane surge this league for this build since the nerf; we do not benefit from cast speed,and the spell damage bonus is reduced.  
We are likely better off with a simple added cold/lightning option as soon as available, but for now AS is ok.
Swift assembly should still be fine in that third link, youll occasinally get a benefit from it even if its not a huge boost.

Mercy Mission can be done on a one link stormblast and will make swift assembly available (B-G), and if you happen to get a B-B-G you can now buy arcane surge

Breaking Some Eggs makes frostblink, orb of storms, and bear trap available which are all desirable (in that order, if funds are limited)

At Brutus if you had arcane surge you can swap it out for added cold or lightning.  Ideal 3L is G-G-B (stormblast, swift assembly, added light)
Flame Dash and Clarity can also be purchased at this time.
If struggling with Brutus, use a totem setup to distract him.  Shrapnel Ballista is available to purchase for our class.

Use clarity if having mana problems but try to keep it at a low level since you may have room fitting it later.
Same guidance throughout the campaign, clarity is an "if needed" aura, preferably low level.

Unlike nearly every other build, entering Merveils cavern does not give us anything worth upgrading to, 3L stormblast with orb and bear is our boss setup here.

----------Act 2---------
Picking up a Herald (lightning, ice, or ash, but eventully we use Ash for a long time), skitterbots, ele focus, trap and mine damage are our top priorities this act.

Herald and Skitter are very important because at this phase our skill tree progression goes on a long drought without damage upgrades, focusing on defense

Trap and Mine damage can replace our added damage support, and ele focus should be leveled until a 4L becomes availabe in Act 3
(Ele focus is safe to use because shock can be inflicted by skitterbots or orb of storms)

------Act 3------
Pyroclast mine becomes available and I recommending switching over immediately. Noticeable QOL+DPS improvement.
Be on the lookout for 4L dex/int bases to go B-B-G-G.  Pyroclast, ele focus, swift assembly, trap and mine damage.  
This carries the rest of the campaign.

Grace also becomes available in Act 3.  If you have taken the mana res mastery on the tree you can fit grace, skitterbots, and herald of ash.

--------Acts 4-10-----------
Minimal changes other than keeping resistances up with gear.  Introduce other skill gems listed in the Skills section as available/needed.
Flammability, shield charge (until we switch from wand+shield over to tremor rod), CWDT+Immortal Call, Flame Dash, Defiance Banner
Be leveling zealotry, determination, and discipline in your offhand, you don't have enough mana for them yet, but you will much later

Only take ghost dance if you can find a bit of gear with ES on it, its a nice cushion to soak up the first few hits which is usually enough to blow up a pack.

-------Early Maps (T1-9)------
 Top priority is fixing resistances and getting as close as possible to 3K life, the more the better
 Second priority from the top is getting a 5L tremor rod, or possibly more cheaply a tremor rod and 5Ling it yourself (30-50c)
1-10c on machina mitts (our main recovery mechanic aside from Pyromaniac)
We just have 1 curse (Flammability) which you should cast with an arcanist brand also linked to frost shield and increased AOE

------------Cheap Red Maps----------
Cheap red maps gear and skill gem setup assumes top priority is a 6L tremor rod**, so other expenses are by necessity minimal to save currency for the 6L
Those other cheaper priorities  include :
 5-30c on 1-3 deafening essences of loathing (mana res efficiency) for armour or helm, just enough to get a resist or two and life or an open prefix for it.
 Alternate cheap option: 5c on an alphas howl (cranking up mana res effiiency for cheap, no more essences needed)
 (Convenience): 20-40c automating flasks
 Xophs Heart (not the upgraded version Xoph's Blood) has been buffed to include Ash on Hit.  
If cheap, this is a great amulet upgrade.  Otherwise generic stat/resist/crit multi amulet.  Anoint with something cheap, maybe Divine Judgement
Some random base jewels with life and some damage or mine throwing speed

Getting mana res on some combination of 2 of chest essence mod, helm essence mod, or sovereignty amulet anoint is a must.
Getting at least 2 of those is enough to let us squeak in all 20 mines plus (if trying to min-max) swapping out herald of ash for a new aura: zealotry.  
If you stay with Ash damage is slightly lower but mana is much more forgiving.  Feel out how easily you're killing things.

**Tremor rod on league start costs between 300-450c typically, which is cheaper than 6Ling yourself if fusings are at 1/3c (1500 fusings = 5c)
But it CAN be cheaper to 6L yourself if you can get fusings at 1/4c or cheaper (375).  Watch the market for both.
Ultimately probably more convenient to buy 6L outright if available unless the price gap between 1500 fusings and the 6L is more than 50c.
Buying fusings is annoying early, too many individual trades.  You could make those 40-50c difference by farming in the time it would take to trade.

------Middle Expenses: Setting Up Long Term Mapping Before Big Expenses-----
Mana Res
We've been relying on helm and/or chest crafted mana res efficiency or perhaps Sovereignty  to fit our auras but we need more auras and a long term mana solution.
For starters we need a rare helmet with both essence crafted mana res AND eldritch implicit mana res
This is because we are losing the chest as we attempt to switch over to a skin of the lords, (assuming new drop rates dont spike the price)
(Skin of the Lords I like with call to arms keystone so we can fit in enduring cry on left click, but plenty of good or just inoffensive options.)

Auras
In terms of auras we have some decisions.  We won't be able to fit determination without either sacrificing a bunch of damage or getting more expensive gear.

I recommend some additional mana reservation items at this point:
Those include combinations of Enlighten lvl 3, a small mana res cluster jewel, a grace helmet enchant, and/or a Circle of Anguish ring with the reservation mod.  
Switch back from zealotry to herald of ash for now, especially if you went with the Circle of Anguish
Our Aura setup is now a 4 or 5L with Grace, Skitterbots, Ash, and a low level clarity, possibly supported by Enlighten. 
You can use chest for Auras for larger link setups, Pyroclast is socketed in weapon

If you got enough reservation efficiency from those options  you can put Aspect of the Crab on a gear piece to drastically reduce one-shots that sneak through Grace.
Without some of those mana reservation tools listed above, you can't fit Aspect of the Crab.


Assorted
Astral Projector Ring is a big QOL upgrade for this build, it causes the nova from your mines to erupt directly under the enemy instead of from the mines when you detonate.
Empower 3 makes a nice upgrade in your 6L, taking the place of increased crit strikes (we're trying to get crit chance elsewhere)
(Power Charges and Charged Mines carry a lot of our crit)
Bottled faith is probably too expensive, but if not this is another big crit carry
Diamond Flask is far easier to get but eventually you will want both

Time to start dipping your toe into the cluster jewels pool.  Ultimately we'll want a large fire, medium trap and mine, and small mana res, but any are fine to start.

Depending on price, maybe a watchers eye with just the grace spell suppression mod for now.


-------Expensive Upgrades --------
This is where we really start to grate the cheese

Awakened and Alt Quality Gems all over the place, 

An enlighten 4 to let you squeeze in both Crab and Discipline for defense
(Rich boys can do the math on getting zealotry in over herald of ash in this setup but it wont be cheap)

Empower 4 for raw damage

Dying Sun and Bottled Faith flasks

+skills amulet with crit multi and sovereignty anoint, hopefully other goodies too
Alternately Ashes of the Stars could certainly make gearing more comfortable and alt quality gems more desirable

2-3 mod watchers eye for any of grace, clarity, discipline, determination, zealotry

Boot implicit+astral projector+and a high rolled abyss jewel can achieve elemental ailment immunity.  Need to figure out bleed.
Easier but more expensive option is stormshroud jewel plus shock avoidance.  Shock avoidance rolls higher values than general ailment avoidance.

Full cluster jewel setup including expensive 3 passive 35% increased effect mana res small cluster

Impossible Escape for nodes around Ghost Reaver (shouldnt be TOO expensive, primary beneficiary are mine builds which arent super popular)

Watchers Eye with 2-3 mods

If you are richer than god you could swap out the circle of anguish for an Anathema while somehow fitting your auras in, then add on ele weakness and one more aura
Third aura could be Assassin's Mark, Punishment, Temp Chains, Enfeeble (depending on offense/defense)

Lethal Pride gives lots of needed strength and damge.  
Can pair with ghost dance, high evasion, discipline, pyromaniac and machina mitts to take Strength of Blood Keystone
Logic:  Life leech barely helps you with a sizable ES pool but you can apply it reduced damage instead, which saves your ES from occasional hits
You still have pyromaniac for big regen if damage eats through your shield, and you're still taking reduced damage 
Meanwhile Ghost Dance should be popping you back to full until you can clear the enemies