[3.7] CoC Cyclone DW Cospri's Malice Frostbolt/Ice Nova Assassin

Weapons:These are pretty self explanatory and a build necessity. Finding ones with max Attack Speed rolls are nice for hopefully saving skill points on attack speed nodes in the future.

Chest:
I think ideally you would want a shaped chest with +1 to Active Skill Gems, but I went for more life/resists on this piece.

Belt:
This item is mandatory for the build, as we are going to be using a Doryani Glorious Vanity jewel to change the Mind over Matter keystone into Corrupted Soul, granting us 20% of our max life as extra max ES. This belt allows our life leech effects to continue on to restore our ES once our life is maxed out, and the leech continues to roll even when both are full!

Gloves:
I know some people will moan at the inclusion of these, but they aren't mandatory for the build. They do, however, increase the survivability of the build immensely. The difference between using these and not having them is night and day. Another option would be Life/Resist Fingerless Silk Gloves.

Helmet:
I crafted this myself, and it is by no means optimal, but the enchant is a big DPS increase, and having the minus cold resist to nearby enemies just buffs the damage even more. Look for life/ES/Resists as well.

Amulet:
I'm using a yoke of suffering to ensure shocks on my targets for a big dps increase. This, combined with a lack of elemental focus support in any of my links, lets any of my elemental damage have the chance to shock, and most of it has over a 90% chance to do so as well according to PoB. I would say this is build mandatory because of the massive dps increase it provides from shocks, but a shaper amulet with "Damage penetrates % of elemental resistances" and life/resists would also be fine.

Rings:
This is where I started to go off the rails a bit and began using an elder ring with LGOH to help with survivability. I am not cursing with Herald of Ice due to lack of links, so an assassin's mark ring solves that problem, and also generates more mana and life on kill which makes mapping a breeze.

Frostbolt > Hypothermia > Life Leech
Enables the frostbolts to go flying, also one of our main sources of life leech.
Ice Nova > Hypothermia > Life Leech
Causes Ice Novas to radiate from our frostbolts and leech even more life!


Cyclone > Cast on Crit > Hypothermia > Increased Critical Strikes > Concentrated Effect > Vaal Ice Nova
This is our main 6-link setup and facilitates casting even more Ice Novas on our Frostbolts.


CWDT > Immortal Call > Frost Bomb > Blood Rage
I am using a CWDT/Immortal Call setup to help survivability, along with frost bomb for cold exposure and blood rage for frenzy charge generation. I stopped Blood Rage leveling at 4 to cap the attack speed increase it provides to keep my APS just under 12. I'm not sure if letting it go to level 6 and making my APS 12.01 is better or worse, haven't played around with it yet.


Vortex > Arcane Surge > Hypothermia > Bonechill
Vortex is instant cast, and with Hypothermia and Bonechill the chill effect is huge, increasing damage taken for enemies within the vortex. Spinning around with Cyclone and being able to throw vortex on the ground is a big dps increase.


Herald of Ice > Discipline > Zealotry > Enlighten (Lvl 4)
To be honest, you can probably drop the herald of ice and not use an expensive enlighten gem and get by just fine. I just like it for the explosions and clear speed. The discipline and zealotry work with our watcher's eye which i will explain next.

Our Watcher's Eye gives us Energy Shield for each enemy hit while affected by Discipline. The other mod I was messing around with in conjunction with energy shield leech, but it proved to be not as useful as I had thought, so it's not really necessary. I kept zealotry though because it was a DPS increase over Hatred.

This jewel placed near Mind over Matter changes the notable to Corrupted Soul, which grants us an extra 20% of max life as extra max ES. It also allows 50% of non-chaos damage to bypass energy shield. This sounds like a bad thing, but it ends up using Life/ES as a sort of Mind over Matter pool instead of Life/Mana. This, paired with the Soul Tether, makes our EHP high and sustainable.

This jewel placed in the witch area of the passive tree will give us enough accuracy rating to obtain 100% hit on cyclone without having to use a Lycosidae. This frees up the slot to use our other Cospri's Malice.

This jewel placed in the Shadow area of the passive tree give us free projectiles for frostbolt, which allows more coverage for clear speed and also more dps when bossing.

This jewel gives our attacks a chance to poison on hit.

This jewel gives our spells fire damage, enabling ignites on each enemy. Paired with the previous jewel, our Yoke of Suffering will be giving increased damage for Poison, Ignite, Chill, and Shock for 20% increased damage.

These two jewels facilitate getting our attack speed to the point we need it to be. Surprisingly I found these for very cheap.

Opportunistic > Ambush and Assassinate > Unstable Infusion > Deadly Infusion
I feel like this is more optimized for leveling speed, as Opportunistic will greatly speed you up early on and facilitate faster leveling. Taking Ambush and Assassinate can also be an option for Uber lab instead of Deadly Infusion, but I preferred to have it earlier.

Kill All

Lunaris/Garukhan for map clear and Solaris/Yugul for bossing