Let's talk about Stormbind

Buckle up, because this turned out long. TL;DR: I think there's a lot of potential here that people aren't exploring because the skill feels clunky at first.

Since the start of this league, it's been my stubborn obsession to make Stormbind work well. I think I've done it (keyword think -- I don't play a ton). Here's a rough POB based off my own character but with some of the supports and gem levels idealized, though I haven't worked on itemization. I'm sure there is plenty of optimization to be done both there and on my passives.

So far I've done up to T10 maps with no trouble save the occasional Delirium death from something I can't see. I haven't had higher maps drop yet, but everything dies immediately, including some metamorphs (literally one-hit). It feels very good in most scenarios.

Before I go into everything, I want to suggest that it probably does better with totems, but there are a few things I want to do before switching. I'll cover those later.

I want to throw out a number of observations that make Stormbind weird:

##Scaling the base damage

• AOE overlap is a huge deal for dealing sufficient damage. You'll be throwing out a bunch of runes, so it's important that as many as possible hit their targets. Not sure what the minimum is for a rune to hit from two runes away, but that's probably required.
• For reference, here's the AOE units diagram. A fully-empowered rune in this build has 36 units. Unimproved has 26. Looks like empowered runes will hit from 3 away, unimproved from 2. That's a max of 36 and 25 runes, each.
• Casting speed is another major factor. When your runes will generally all overlap, the more you can throw out, the better.
• The high cast speed also means you can treat your cursor as a kind of paintbrush of death. You'll be making a lot of sweeping motions if you want to maintain good clearspeed.
• You might think you should run Herald of Thunder, but this actually lowers your damage when you use the new shield spell, Arcane Cloak. Pop this on bosses for damage when you need it. It doesn't interrupt channeling, so it won't trigger Rune Blast.

##Scaling Rune Blast

• You typically don't need to charge this at all. Just right-click to pop the runes and watch the screen explode.
• Building around Rune Blast can drastically alter the effectiveness of single-target damage. By my calculations, the linked build has about 70% more dps casting rune surge on existing runes than creating new runes. However, it sucks before you equip...
• Doedre's Malevolence is far-and-away best in slot for its effect on Rune Blast. The flat +50 mana cost (doesn't get multiplied by anything) is vital to powering up your runes, and nothing else I'm aware of comes close, because...
• Rune Blast doesn't allow very many supports. As a result, you need to run a separate 4-link to have any kind of multiplicative effect at all. Even with supports, the majority of the cost comes from the gloves.
• An alternative support setup might be on a 5L staff, with faster casting, arcane surge, CWC, conductivity, and infused channeling. Blood magic will also support it, but the huge cost makes this seem like a bad idea. You could put another skill into the 6th slot for some extra clear or utility if you wanted. You could put two spells in (or a spell and support) if you had a 6L staff with built-in Faster Casting.
• Self-cast Stormbind has the distinct advantage that it can be pre-cast to inflict a lot of damage when an enemy becomes targetable.
• Blink spells can be cast while channeling without interrupting the channel (or at least frost blink can be). Useful for laying a trap and then drawing an enemy into it, such as a boss, in a sense precasting your damage.

##Endgame Items

• The obvious choice here is Indigon in the helm slot. This will take your damage to crazy heights, as the mana cost scaling will charge your runes faster. The typical downside of this item just scales your dps further, kind of like with Archmage.
• Fevered Mind also seems like a good bet, but I'm worried that the mana costs could spiral too quickly.
• As the build lacks much physical damage reduction, it might be good to get % physical converted to some element.
• Stack penetration. At present, the build suffers on enemies with high lightning resistance, but there are plenty of items out there to grant that. They're just costly.
• Less costly but probably not ideal is the Agnerod with 20% penetration.
• A hyper-offensive build might go for Carcass Jack, though I again advise opting for phys conversion. With helm slot taken by Indigon, your best bet for this is on the chest slot, probably with Lightning Coil.

##Damage Totals

There are some more complex calculations that could be done here, but I'll make things simplistic:

• This build in its current state deals 3.78M dps just channeling Stormbind itself, assuming you blow it up before you start wasting runes.
• Assuming there are runes to be charged, the build deals 6.4M dps while channeling Rune Blast.
• These numbers are slightly inflated by the guard skill, but good usage of it will maximize its uptime during critical portions of the fight.
• These numbers will skyrocket with an Indigon equipped.
• This is a lot of damage...

##Totems???

Thus far I've been playing self-cast. This has a few advantages:

• Pre-cast on bosses
• Leech (both life and ES)
• The best offensive ascendancy picks are also pretty defensive - you lose a ton of AOE and ES (edit: I decided it was probably best not to spring for the power/endurance charge ascendancy nodes going totems, so you don't lose AOE and ES, but you don't have leech, and you don't have endurance charges)
• Harder to fit Arcane Surge with totems unless you go for a 2h staff (important for mana regen)
• I don't like totems

However, with Indigon scaling your mana usage and damage, the dps from Rune Blast compared to Stormbind will become much higher. The continual runes from totems will allow you to charge Rune Blast whenever you want, and generally speaking this seems like the ideal scenario.

I found an Indigon Calculator that seems to show that by the time you have cast for a total of 1.1 seconds in the last 4 seconds, you will be charging all 9 runes simultaneously, which is effectively the max (I think - not sure if it spreads past the 3x3 square).

Simultaneously, if you summon all 4 totems, they will be laying down 44 runes per second collectively at 133k/rune. If you were to detonate all of them at all times, that would be 5.8M; however, you deal 10.7M dps while channeling Rune Blast, more if it scales beyond the 3x3, and that's not including Indigon spell damage (133k/rune * 9 runes * 9 times/second).

#THANKS FOR READING MY BOOK-LENGTH POST

There's a lot of damage here. I think it merits more builds.