Firebreathing assassin CoC dagger Flame Surge - breath serious burst!

At least 4 linked Voll's protector
Crit + Attack speed dagger, preferably with spell damage

Flame surge mechanism
Flame surge as the unique attribute of dealing 50% more damage to ignited targets. The skill itself has very high base damage, similar to Arc. However the 50% damage against ignited targets raise the damage much higher than Arc itself.

In this build, Flame surge's damage is multiplied with the 50% more damage to ignited + 50% against shocked + 69% more area damage using concentrated effect.

Three dragons helmet will provide the shock status on everything you hit with fire, which is basically every spell in this build. Herald of ice aura will provide 24/7 ignition on mobs, this can however be replaced by simple flat cold damage on gear(1 flat cold is plenty to put iginite on mobs).
All this is the skills damage without gear boost or passive tree boost. Which makes the skill a extremely deadly burst.

Why focus on single target?
Most CoC dagger builds out there use Spectral throw on their 5l or 6l to create massive AoE damage. I personally find the ST slightly insufficient at single target fights(boss, rares, rogues). ST requires the player to be at melee distance to be able to shotgun burst damage any single target anyways and the longer the fight, the more dangerous it gets for relatively squishy builds like CoC.
This is the main reason I choose to focus on being able to burst down single targets within matter of seconds to realize the "good offence is the best defence".

What about AoE clear speed?
In this build the clear speed is very good, perhaps not as fast as CoC dischargers or those super high end crit builds.
Spectral throw is on a 4l to provide AoE damage and with the gear/passive boost it is more than enough for clearing trash-packs fast.

PLAYSTYLE
Clear packs using spectral throw + fireball
Do not attempt to facetank the tougher mobs, find an opening and rush in to burst them down before they can harm you. Hence the assassin title.

Popping defensive flasks like Jade flask or resistance flasks while charging in, the bosses are usually dead before the flask effect runs out.
So far running the maps is very easy, the damage feels very swift, which provides safety and clear speed. Everything below level 76 is a breeze(as long as the map mods are not crazy), and on level 76 maps it's required to proceed with caution, but this applies to many builds out there.

Here's where the damage is boosted for real, short summarization:

205% Spell damage (including fire damage, elemental damage and spell damage)
220% Increased critical strike chance
115% Increased critical strike chance for spells
190% Increased critical strike chance with daggers

Acrobatics, Phase acrobatics, Ondar's Guile for defensive boost

https://poebuilder.com/character/AAAAAgYAl5dFfOUZtDj79Yw25Y6ksV3ynWMmlWHiVUsWv3BSidNw1Q5IY0Pb50cG8uEs4axmuT7YdhGWkBuaE3BW29QHHklR8NWVLp2qYqy0xWyMBbXC7DpCS3jdqDBx1CP_3iT951RRR42_1op_KzB8f8YnqUyzLR-VIMHzoqNQMNteBAeD2zpYVcasmOxVKo1JGzbY8WxNkiP2jX1W-nfXSn2Hdmeg_MW5fIwL7LA2PfPqKgvB1aR43vjQ9UGWrrMFQiycaxdqQ8BUvOoI9A==
Currently planning to take the spell block circle near the witch starting area and the trinode area near dagger circle on right of the tree. Once that is reached I'll test with Rathpith's and Rainbowstride

Other future thought is to take Elemental equilibrium, if i get flat cold damage (also used for ignition). This would help out against resist mobs considerably.

Damage
Single target
Double strike + Multistrike + CoC + Flame surge (5l Concentrated effect) + (6l Fire penetration/Life leech/Increased critical chance/Increased critical damage)
*Keep double strike at level 1 for lessen the mana cost

Alternative Single target
Cyclone + Blood magic + CoC + Flame Surge + (5l Concentrated effect) + (6l Firestorm/Fire penetration/Life Leech)

AoE
Spectral throw + GMP + CoC + Fireball/Firestorm
*Keep spectral throw at level 1 for lessen the mana cost

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I'm currently using double strike, as it feels more swift to execute the targets and the proc per second feels better than cyclone. However the innate mobility of cyclone can be very useful. It is however required to use blood magic on cyclone, just as it's required to use multistrike on doublestrike. Same color sockets so you may test for your preferences.
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Aura
Grace + Herald of ice + Reduced mana

Cast when damage taken
Cwdt + Enduring cry + Immortal call + Increased duration

Mobility (optional)
Whirling blades + Faster attack (+ Blood magic - optional)

Curse
Flammability or Elemental weakness(preferably with quality)

I got extremely lucky to fuse my own 6l voll's. But up until lvl 80 i used 4 linked voll's protector and the damage is still excellent.
Doryani's is not absolutely required but without it you'll have to spam surgeons flasks (more frequently at least) However acquiring a good life based belt can be very helpful on the life pool and res stats.

*I'm planning to use Rathpith's in future upgrade, while taking the block/spell block circle near witch area. This would grant me +- 20% spell block on top of the 46% spell dodge. I'm also considering using Rainbowstride to boost the spell block but i'd lose flat life, 16% spell dodge and 600 evasion for that trade. I'll have to see how it works out later.


Flasks

Surgeon's hybrid is used to maintain mana using spectral throw and double strike. It refills very, very quickly so it's simply a matter of getting used to it.

****To be updated soon, this section is currently outdated***
Screen shots will be included soon
Current tool tip dps on the main skills(with 6 power charges)
Flame Surge(lvl19) = 3535 - 5306 (+ Herald of ice 257-343) = avg 4720 per cast
Firestorm(lvl19) = 834 - 1256 (+ Herald of ice 52-69) = avg 1105,5 per ball drop
Fireball(lvl17) = 678 -1018 (+ Herald of ice 85-144) = avg 962,5 per fireball
As we all know, the tool tip is far from the actual dps in CoC builds.

Accuracy = 88%
Crit chance on full power charge = 78,3%
Cyclone attack per second = 3,2
Spectral throw attack per second = 2.6

Here's an attempt to roughly calculate the DPS
I was told that actual hits per seconds on cyclone is roughly double the attack per second, let's use that for the calculation:
6,4 * 0,88 * 0,783 * 0,66 (lvl 19 CoC) ~ 2,9 proc of Flame surge
4720 * 1,5 (ignited) * 1,5 (shocked) * 2,9 = 30798 fire damage per second
This calculation is without firestorm procs on cyclone hits, because I'm a bit fuzzy on the proc chance of dual spells

The kill speed on map bosses below level 72 is approximately 2-4 seconds and on map bosses below level 75 is max 7 seconds burst.
Videos will be included later.