Level 100 Crit Spectral Shield Throw Assassin^3.27

Notes

Spectral shield throw SST and Spectral shield throw of Trarthus SSTT

This is a glasscannon build, at my gear level i can survive a few hits from normal things, major boss abilities will likely still 1 shot you, but with enough damage and speed it is comfortable enough to casually play into the upper 90's
Most of my builds I find cap out at around 92 just due to deaths, this one is by far the most well rounded.
I comfortably leveled to 96 normal mapping, then 96-100 i farmed witnessed synth maps (about 200 maps but they more than pay for themselves with maven witnessing and selling cortexes)

You could reasonably drop haste, pickup grace, add a suppression/evasion watchers eye and pick up a bit more evasion nodes to get a lot more evasive but I honestly didn't find it much more survivable than just building for damage.

This is my leaguestart build and it scales all the way into ubers / T17 (not recommended to farm t17s but it can do all of them, recommend only fortress) . I have done 40/40 and all ubers except for Incarnation of Dread. 
ubers with phases, like dread or uberuber elder are very hard, ubers without phases die before they attack.

two configs included, 
one with all of the configs are unchecked
one with buffs we can keep up, this build does chill, intimidate, shock, powercharge, frenzy charge, pointblank, close range, onslaught, have tigers, cover in frost (graft) rage is disabled, you will get some from shield charge but it wont be up for bosses.

with no mana cost, 100% phys conversion and awakened WED for ele reflect immunity and recovery from polymath, this build can do all normal map mods ( shield charge will still kill you on ele reflect if your not paying attention)

SST for clear gem swap SSTT for large single target (ubers/t17), even up to guardians with my gear i can 2 shot them with sst

SSTT mechanics
you throw a shield, it hits a target and then pulses 4 times with secondary projectiles that do 50% of the damage of the main projectile, so your expected one attack hit damage is 3x your normal hit damage.
snipers mark splits your shield by default into 2, with the ranger mark effect wheel and 4 mark effect tattoos you get 50% effect for 3 splits. for 16 tattoos and the mark wheel you get 100% effect for 4 splits.
The secondary proj can shotgun just like with tornado shot. with 4 splits you hit with 1 shield, then 4 split shields shoot 4 proj for 16 secondary proj hits, the expected hit damage with 4 splits is (16*.5)+1=9x up from 3x
The distance the the snipers mark split projectiles travel from your target is based on your distance from the target, if you're an inch away from your target they split an inch away, if you're 4 inches away they split 4 inches away.
This lets us help ensure the shotgun by going pointblank, you can go farshot but you would need a lot of proj speed to ensure the secondary projectiles overlap, but this would also reduce the likelihood they actually hit the target.

this pob has my SSTT hit damage as 11.9m doing ~60m dps the actual ingame damage is likely closer to 300+ m

mana costs: get 2 -7 mana cost rings, 20% reduced mana attack helm implicit, Ranger mana cost wheel, 10% mana cost mastery, inspiration gem to get 0 cost SST and shieldcharge

Gear
going for 100% mark effect is really heavy on resists and attributes due to tattoo usage, build works fine with 50% effect if gearing is tight.

need lvl 24 gem for large breakpoint on SST and SSTT base damage scaling

Chest: assuming a lvl 21 gem you need +3 total
An easy way is to get a +2 projectile corrupted lioneye chest  and a +1 amulet, (also gives a pierce 7 link, buy corrupted link with tainted currency. very cheap even on day 1-2, need luck with tainted fuse.)
or any chest with 21 gem  and replica dragonfang +3 ( you lose a lot of offencive stats from amulet)
or +1 socketed or dex gem rare chest +2 amulet (much more expensive amulet, lose 7link but can have higher defences on chest) 

Weapon: no local weapon mods effect SST BIS weapon for this build damage wise is a near perfect grace of the goddess wand, but it needs to be very very well rolled. and good ones are very expensive.
buy shaper harpy rapier, alt/aug/anul until t1 global crit multi rare with no prefixes. if you hit a good suffix you can keep it but many dont effect SST ( Dex, frenzy charge, onslaught are good)
craft cannot roll attack. slam 3x prefixes, if you did not have a second suffix at step 1 you will need to slam another random suffix. only shaper mods and gem mods can roll. 
Very likely but not 100% to hit the mods we want. % phys as cold, % phys as fire, elemental penetration. Shaper mod penetration is global, crafted weapon attacks penetrate is not.
finish by crafting either double damage or crit multi with unique nearby. about 1.5 div per craft attempt.

*you should be able to do the same thing on a shaper dagger, lose the 35% multi implicit for 50% global crit, daggers get % phys as lightning rather than fire, helping with shock. (i have not tried this i dont know what other things can roll)*

shield: we have to use emperors vigilance for crit scaling, build works just fine on a normal 20% quality. each 10% increase in quality is roughly 8-9% more effective dmg. 
normal league a 29% quality steel kite shield can be a few div then omen of fortune (early league like 4-5 div) to make it emperors vigilance. 30% quality bases are usually pretty expensive and people flip them...
40% quality foulborn is bis, hopefully goes core.

rings: double damage mods EDWA/crit multi, need -7 mana cost, ideally life and res

ammy: need +1 phys or all gems, EDWA/crit multi, res, attributes, life if possible
anoint, i like heart of ice for passive damage and cold pen.
Whispers of doom is likely BIS if you can squeeze in a frostbite on hit ring, I can not.

boots: nothing special, i like chill immunity,heavy, ressits, life, action speed implicit, phys as lightning or cold implicit, lightning lets us shock

gloves: best gloves would be temple damage against a chilled monster, 35% cold conversion, attack speed, accuracy and life. but these are extremely expensive.
35% phys to cold, attack speed, accuracy, life, cold
can craft with fractured life, essence attack speed until accuracy, lock suffixes veiled chaos and pray for cold conversion, might not be worth it. i did get lucky with mine early in the league.
glove implicits
need 25% phys to cold to compete conversion (35+25) gloves +40% cold mastery
rage: this build kills ubers in 3-5 seconds rage will not stack and is not meaningful when needed. nice but kinda pointless
attack speed: Good 
intimidate: Good (SSTT hits like 50x a second when shotgunning so intimidate should be up even at 15% chance per hit)

helm: life, accuracy, essence mana reservation, implicit cold pen and reduced mana cost of attacks.

belt
rare: stygian vice, life EDWA, dex/str, res
bis damage: Ryslatha's Coil is like 20% more damage
utility: mageblood is nice for zoom thats about it, HH also is fun..

grafts:
Basic setup, 2x tul grafts with 10% cold pen
more expensive 2x tul grafts with 10% cold pen, freezing tulgraft with chance to cover enemies in frost on hit
maximum dmg (not worth imo): 1 freezing tulgraft with 10% cold pen and chance to cover enemies in frost on hit and 1 jolting esh graft with attack speed, +4 graft levels and +1 max damage to get 40% maximum attack damage but 20% damage taken.

jewels:
seething fury, mandatory for crit shield abilities
watchers eye, hatred cold pen + precision attack damage or attack speed, just the 2 mods is fairly cheep
the light of meaning, + phys is bis but +cold is way cheaper and can get pen corruptions easier
polymath forbidden flame, a lot of damage + good recovery, normally not very expensive
lethal pride, try to get 3x % double damage with strength, resist or life
cluster setup needed for extra jewel socket, can go cold cluster for pen or attack shield cluster. Projectile cluster for medium.

suppression is not mandatory but is nice, as a glass cannon build there's a good chance you'll die anyways.

ascendancy
The whole goal of this build is to use SSTT to shotgun ubers and kill them before they attack, while using normal SST to clear in a similar way to a bow build with fast ranged attacks.
Why assassin?
I originally made this build in Legacy of Phrecia as a Whisperer Ranger to get rage, free awakened fork and charge stacking. Assassin was what worked best to try to recreate that build in the next league.

Assassin gives a LOT of front loaded damage with for the jugular and opportunistic along with charge generation. knife in the back is nice leveling and early game for high crit against full life.
Shadowed blood is great for early game with damaging ailment immunity but I choose to swap to farruls bloodline huntleader for 35% attack speed and 120% crit. 
Power charges and farruls tigers both stack VERY quickly and will likely be up 100% of the time even on single target.

trickster could work but not optimal without changing a lot to go ES based and would need to use a different chest, lioneye is armor based.
elementalist/golemancer could work but would fundamentally change the build to something completely different.
slayer/champion could work but these are likely better suited to the phys, impale, bleed variants many people do.
ranger, pathfinder is generally ok but nothing special, warden tinctures don't affect shield attacks and avatar of the wilds likely won't be up for bossing. 
Deadeye is my second choice. It makes mark scaling much easier, frenzy charge and gathering winds are nice but compared to assassin you still lose like 60-70% more damage (including polymath), for a bit of utility reason to go deadeye.

Gems
Main attack, SST and gem swap to SSTT for single target (see skills for my preferred links)
awakened fork is VERY nice for SST clear but also very expensive and not needed

Shield charge and frostblink for movement/teleportation, shield charge also scales with almost all of our scaling and ends up doing a lot of damage. 
I have rage linked to shield charge, mostly just for the attack speed. rage does stack while mapping but isnt needed and wont be up for bossing. rage in shield charge mostly just inflates Poe.ninja dps. you could put in another awakened wed for immunity there too.
Frostblink linked with bonechill and unbound ailments to increase the chill damage bonus for cold. frostblink onto/behind bosses for extra damage.

auras
precision, level 1 just for watchers eye buff (unless you need accuracy)
hatred, phys as cold and watchers eye
herald of purity, more phys scaling

haste or grace depending on if you want speed or evasion. I have a suppression grace watchers eye from when I tried to make the build more tanky. lol

Lightning golem, not needed but free extra attack speed for bosses. Just dies in maps.
cwdt immortal call, i like to pretend it helps but it probably doesnt.

enhance bloodrage for attack speed, bloodrage in a weapon slot so you can weapon swap to disable the degen.
enhance snipers mark, needed for SSTT shotgunning


Flasks:
(my character is crit capped without the diamond flask however without powercharges and farruls tigers i am not, so for engaging bosses its still nice)

Diamond and silver are very nice for smoothness,
Taste of hate for damage
whatever other flasks you prefer.
you don't need a quicksilver with our attack speed and shield charge.
Once you get polymath you can drop life flask, if using mageblood a %life regen flask is very nice to counter bloodrage.

important masteries 
runegraft, 10% more attack speed with offhand (i use an unneeded life mastery)
accuracy, more accuracy at close range, or against unique monsters, likely needed for accuracy cap
cold, phys conversion 40% for full conversion
mark mastery, single target frenzy charge generation
mana mastery, 10% reduced ability cost needed for 0 mana cost
suppression, lucky, very hard to hit a good suppress amount without.

ok masteries just for polymath and damage
physical, more maximum attack damage
elemental, resist inversion
crit, multi against uniques
reservation, % damage
life, +life

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the main thing i've heard from people whispering me trying this build it is that SST is kind of annoying to play because you have to actually aim it, the hit radius on the projectile it is actually quite small,
attack speed helps a bit. But if you are expecting something like a wander or bow builds level of clear this is worse than that. you get used to it and the pierce + chain makes it work well in narrow maps.