My take on starting with an Arc/Spark OoS Inquisitor for 3.17

Do note that all of the dps numbers shown in this default tree are without any DPS from items, the normal staff equipped is only done so to enable some values from the tree, and the rare armour was added to give a better idea of final health/armour/ES numbers with mediocre gear. I think hitting 1m DPS with this build with budget bin/SSF items should be fairly painless after the buffs. I know that 1m DPS is no world beater nowadays, but this build should scale pretty well with good gear, and being this tanky ought to count for something. --Items-- look for a Crusader/Shaper Amulet, as you can swap over to a Petrified Blood with a lighning damage leeched as life mod, for even more tankiness. Do note that the DPS difference between going to the upper right for Melding/Nimbleness and going down for Iron Will/Constitution is only due to the difference in Strength between the two, and that it might be better to go for the former pair on non Petrified Blood versions only if you can get Strength from Gear. Blizzard Crowns and Sacrifical Garbs have fantastic implicits for DPS, and compete with Crown of the Inward Eye and Inpulsa's Broken Heart in their respective slots. Mark of the Shaper is arguably BIS with an accompanying Elder ring, but a Lori's Lantern is worth considering if you are running Petrified Blood. I don't think Repentance is really worth it for the regular/Petrified blood version, but it can ge a decent enough stopgap assuming you can meet the attribute requirements. You should probaly never use Agnerod West, as a couple Torment/Misery essences on an Imperial Staff should outpreform it on average, thanks to the addition of cast speed. If you get a 6 link drop early on though it's a decent stopgap I guess. Getting Tailwind/Onslaught is a nice boost to DPS, try to get these if you can. Cluster Jewels are definitely an option, but you'll have to figure that out for yourself as I would only bother with them if I happened to drop useful ones in SSF, which isn't a guarantee given how little I enjoy doing Delirium... Regular gear affixes should be pretty straightfoward, simply prioritize lightning damage (be sure to have "to spells" and not local attack on your staff, of course), cast speed, +gem levels, crit multi (and maybe some crit chance), mana regeneration rate, etc.. Should be easy enough. Strength is also nice to accompany Righteous Providence. A little bit of extra flat mana on items will help significantly with buffering your spellcasts against going OOM, and should help enable the addition of Defiance Banner. You might also be able to get away with dropping the "Vitality/Clarity has 100% increased Reservation efficiency" mastery nodes on the non Petrified Blood trees with enough mana. --Gems-- The difference between arc and spark here is just a matter of preference I think, Arc feels smoother to me personally but Spark does have a slightly higher cast rate which might help single target. Thankfully, all of the supports between the two gems are the same, so you can level the other in an offhand and try both with minimal fuss. Faster Casting/Swift Affliction on Lightning Warp appears to be a tossup for which is better on PoEninja, but in this instance I think Swift Affliction will be better given our stacking cast speed on this build. I leave that decision to you, however. If you find yourself socket starved, you can even skip both, which might be useful on petrified blood setups to squeeze Increased Duration/CWDT onto your Molten Shell. Remember to keep Swift affliction at level 1, to keep dexterity requirements to a minimum, if you do use it over faster casting. A full softcore build could probably drop Determination, and replace it with Zealotry while swapping armour tree nodes for damage ones, but I prefer to build a little bit tankier and damage after the 3.17 buffs should be fine. Faster Casting might be/probably is better than Added lightning damage for our Arc/Spark Setup, but I'm not 100% certain on that, especially without the new gem numbers here in PoB. My gut says Faster casting is better, but diminishing returns from extra cast speed obtained on gear might push it to being less effective. Prioritize 6 linking OoS first, of course. Gem Priority for skills is listed in descending order for each skill. I prefer having Molten Shell on left click, but CWDT is perfectly fine as well if you prefer to have it autocast when you probably need it. --Tree/PoB-- I went Inevitable Judgment over Instruments of Zeal, as I would rather not have to juggle Fanaticism uptime. I'm sure there are plenty of others that prefer the massive boost to cast speed and reduced mana cost and have built accordingly. The most important stat to watch for QOL on this build is probably going to be the mana regeneration rate, you will want to keep this above your mana cost * your cast rate. Before cast speed from items we're already running pretty close to not sustaining, so you will likely need some mana regenerastion rate from items to keep pace with your spending. The Righteous Decree node may or may not be mandatory to meet these metrics without certain items, and was added to the main trees mostly as insurance. The other large issue this build will face is its lack of stun and ailment immunity, but that's a problem for hardcore to solve. I'll just do what I can with flasks/pantheon and call it a day... Notable annointment candidates include Doom Cast, Assassination, Tranquility, Disciple of the Slaughter, True Strike, and Hematophagy (if you are going Petrified Blood). Dreamer might also be a good budget option if you want/need more Qol. Glancing blows Might not necessarily be the best option in terms of damage mitigated, but I think I like it here a) for the "spell damage per spell block" mastery node and b) for the more consistent incoming damage with a small built in hedge against block reduction map mods. But, to each their own. Damage varies more or less negligibly between trees, in my opinion. As an extra note for both of the Glancing Blows trees, the northernmost block node cluster is skewed towards attack block being overcapped more than spell block, as it appears that the -block map modifiers don't apply to spell damage according to PoB. Simply switch those two nodes if this is not actually the case. Of course, it also has the benefit of keeping you clock capped if you haven't crit recently, but that shouldn't be important. The Lightning mastery can be swapped to +1 chain if you have sufficient critical strike chance, or possibly "shocks increase damage taken by up to a maximum of 60%" if you can somehow get your shocks to be that strong. The staff mastery "life/es on block/spellblock" may or may not be worth it, but I'm keeping it anyways. Feel free to disagree, though. I'm aware that the shock multiplier in confguration is probably too low, but I was being conservative there. The same applies to not having power charges checked, even though generation should be fine with Whirling Barrier. Helping Alira is probably your best bet early on, but I think I prefer grabbing a jewel socket over her bonuses once you hit endgame. Your call, though. --Other-- This build assumes you have leveled with OoS, but if you haven't, just craft a pair of level 20 flat lightning wands and dual wield with an Elemental Overload setup until you can get a decent staff, then respec into the appropriate staff nodes. There are plenty of guides that go into more detail on this front, as OoS has historically been one of the best leveling skills in the game. I have to admit that I have not played this build yet, and all of this is purely speculative, but I think I've played enough to have a good idea as to how to get a build to function well wnough. Of course, I might have missed something, and if I have please let me know either on Reddit or in game. Also, as a small disclaimer, I am in no way responsible for ruining your league start, especially since this starts leveling with OoS anyways, which makes swapping to something potentially better trivial. --Midocelli