[3.10] Storm Brand + Archmage Assassin

This will be my first ever build guide, and this character is by no means fully equipped yet. But even with how unfinished my gear currently is, I've been able to complete all bosses and simulacrum with this build, so that should speak for how well it performs.

Introduction
This build started out as an Arc + Archmage build, but slowly evolved into a Storm Brand build, since this was my first league to go up against Sirus and the other Atlas bosses and I wanted a build where I could focus on positioning while my damage would go automatically. Storm Brand was perfect for this, and it worked quite well.
Most brand builds usually use the Heirophant ascendancy for its good mana scaling and it has a node specifically benefiting the use of brands. With the introduction of cluster jewels, I was able to achieve similar bonuses as the Heirophant ascendancy purely by using the right medium cluster jewels.
The current budget for my current gear is quite expensive, probably nearing 30ex+, so while this version is not cheap, budget gear can be used and this build should still perform very well.

Pros + Cons
Pros:
- Very good survivability, with 6k+ ehp, fortify, and 50%+ block chance for both attacks and spells (using the Glancing Blows Kiloava passive).
- Easy to play, lets the player focus on positioning rather than finding openings to do damage against difficult bosses.
- It's a bit of a different flavor for a brand build.
- Dual wielding Void Batteries and a bit of passive respeccing can blow DPS through the roof (sacrificing survivability).

Cons:
- Boss damage isn't superb, but it gets the job done.
- Not very cost effective.
- Mana scaling on an Assassin requires more passive investment than Heirophant. I haven't tried it, but it may be possible to do some reworking to not use Archmage and maybe go into more crit.

Bosses
This was my first league where I faced Sirus or other atlas bosses, but in the end I was able to beat all bosses (Sirus at AL8, Elder, Shaper, Uber Elder, Uber Atziri) and beat lvl 20 Simulacrum after a couple tries. It wasn't a smooth ride, and this build isn't the best at boss killing, but it got the job done.

T16 Map Clear (Shrine): https://youtu.be/x4bIKp7XFH4

Gear
For gear, there are a few essential uniques that help out a lot, and their bonuses are hard to pass up for a good crafted rare. The most important unique would be our Cloak of Defiance.

This unique gives us extra mana, mana regen, the Mind over Matter passive node, and an extra 10% of damage taken from mana before life on top of that. It's easily a best in slot. the other essential unique is Atziri's Foible, an amulet that gives us insane mana and reduces the level requirements for gear/gems, saving us a few passive points.

I allocated Arcane Guarding, since we are going for high block.
Optional uniques include Skyforth,

which with our mana makes us practically immune to stuns, and it gives us mana to top it off. The lack of life regen is unfortunate, but it saves us a passive point (not grabbing Zealot's Oath). Mindspiral is a great choice for helmet, but due to my lack of resistances I grabbed a rare hubris circlet with the enchant "Storm Brand Damage Penetrates 12% Of Branded Enemy's Lightning Resistance" and rolled some resistances with high energy shield. Mindspiral also lacks in energy shield, but depending on your maximum mana you could get more energy shield from Mindsprial. Here is my current helmet

The last big ticket item for this build is a rare Shaper Spirit Shield with "Recover 5% Energy Shield When You Block". This is a really great mod for any block build, and boosts our survivability.

The rest of the gear is really up to you, I grabbed a Crusader Prophecy Wand that I still haven't crafted to my liking, but I would like to have a wand with lightning damage added to spells with lightning penetration, along with some mana and more spell damage and ideally some crit. My rings are both Cerulean Rings, one of them is a Shaper influence, as I'm currently trying to craft a "Curse Enemies with Level 12 Assassin's Mark on Hit", but I don't have that crafted yet (The current ring is absolute trash, just know that a shaper ring with Assassin's Mark curse would be good for this build). My gloves are just basic Fingerless Silk Gloves, going for energy shield and resistances, and same with my Crystal Belt. A Shaper influenced Crystal Belt could boost energy shield a ton, but I am still trying to craft my other gear so I haven't finished that yet.


Flasks are pretty typical, I have a couple life flasks, a basalt flask for damage, and a single mana flask just to boost my regen a little. The only real game changer is a Wise Oak flask, and make sure your lightning resistance is the highest uncapped. A Cinderswallow Urn could also be added, but I haven't gotten one of those yet this league. Here is all my gear that I used in each of the gameplay videos.



Passive Tree
PoB Pastebin: https://pastebin.com/vSVsXCQK
Note: In the PoB tree, the jewel socket near Mind over Matter is a Lethal Pride with Kiloava passives. This transforms the Mind over Matter into Glancing Blows.

The passive tree is focused on getting as much mana and energy shield as possible, while some changes could be made to grab some more crit nodes. The cluster jewels are there mostly to benefit our brands and give us some mana and es.

Gems and Links
Storm Brand - Lightning Penetration - Energy Shield Leech - Controlled Destruction - Archmage - Concentrated Effect

Vaal Righteous Fire - Tempest Shield - Increased Duration

Shield Charge - Fortify on Hit - Faster Attacks

Brand Recall - Flame Dash - Second Wind

Arcane Cloak(Lvl 9) - Cast When Damage Taken (Lvl 4) - Increased Duration

The Righteous Fire and Tempest Shield are totally optional, but I highly recommend the other skills, as they all work extremely well together.


Conclusion
I'd like to end this by saying in its current state, this build is more of a concept than finished build. I'm lacking in resistances and damage isn't peaked, but it's good enough to do all the content so I thought why not post it? Feel free to throw out suggestions or thoughts and let me know what you think! I plan on making another build guide for an Arc + Archmage Trickster SSF started build for next league, so any tips on making better guides is also welcome!