3.6: 3.9 coming this league Dark & Light: Uber Elder Killing Staff Inq. Guide

There are many many good gems for Purifying Flame. The ones in the combination I have appear in POB to yield the highest Shaper dps. As I said use Empower if you have the craft, which I highly recommend. You use Combustion Support instead of Elemental Focus Support until you have the Warlord's Mark on hit ring, because then you get Storm Brand CWDT to apply the Combustion Support debuff.

This build needs Warlord's Mark for mana leech, as there are no other sources of spell mana leech and it doesn't build any mana regen (not to mention purifying flame costs a lot of mana). It also gives life leech, which means no need to go buy or craft and expensive piece with fire damage leech and good stats. Before you have a warlord's mark on hit ring, you will want to blasphemy it.

Wave of Conviction is new in 3.6 and a must have for lightning and fire damage builds. Some people use it on traps, totems, or Cast When Damage Taken set ups. Because I do not have Flame Dash in this build, and have better options for my main ability, I have decided to self cast it to get Arcane Surge. With increased duration its debuff and arcane surge last fairly long, and of course you will always have flammability on the boss if you recast this every 7ish seconds.

Leap slam is a primary focus of this build, you get enough attack speed naturally from staff nodes and your ascendancy that it is not to slow, and yields fortify. The culling strike is not necessary, but gives you culling strike and attack speed. If you had Elder gloves with Faster Attacks Support on it, and took off Culling Strike, you could put your Blasphemy on your gloves. But I feel like by that point you will probably have the Warlord's Mark on hit ring.

In my boots I only have two gems, as you will find out its because I use Bubonic Trail. If you weren't using these you could have more options there too.

There is some variability in the build, you could easily play with the skill gems to fit your desires. But these seemed to work the best for me after some testing.

There are very few gems that are actually applicable to Dark Pact. Other than the one's here is power charge on critical (which I have on a staff) and added chaos damage (which POB's for less than the gems here). By my calculations these are the best gems for Dark Pact.

Warlord's mark is the only way to get mana leech for spell casters. And this build need's mana leech, as I do not take any mana regen (and it would take a lot regardless). In addition, getting chaos life leech can be expensive and is often on sub par items. So we kill two birds with one stone. You need it up all the time, thus why I use blasphemy until I get an elder ring.

Leap slam is a primary focus of this build, you get enough attack speed naturally from staff nodes and your ascendancy that it is not to slow, and yields fortify. The culling strike is not necessary, but gives you culling strike and attack speed.

Zealotry is a very good dps aura, and gives ranged consecrated ground on bosses. You could use haste if you want for less damage, but another cool down and attack speed. Once you have a Warlord's Mark on hit ring, you can use an enlighten (level 4) and Haste if you want, but its a lot of money and not really necessary.

Wither is a huge dps increase, and a totem is the only real way to deliver it. With faster casting your totem needs to survive for about 2 seconds to get the max debuff, and even if it dies you do not need to recast for about 3.5 seconds with increased duration. (only use it on bosses).

Other than these you can do pretty much what you feel like with the other links (the chest in particular). If I am wielding a two hander I like to have a six link cast when damage taken Storm Brand for debuffs. This allows me to not have to worry about casting it. It will yield almost 100% uptime on bosses if you are melee (which this build is) due to taking auto attacks (even if you dodge all the spells). But this is not at all necessary. But you could easily self cast storm brand for debuffing bosses. Another thing you could do is have a deeper cast when damage taken defensive set up with immortal call, increased duration, and a summon stone golem. The sky's the limit as long you get your damage curse out and have the tankiness you want.

In my boots I only have two gems, as you will find out its because I use Bubonic Trail. If you weren't using these you could have more options there too.

To get a bunch of damage on the cheap (like 9-10 ex (including the 6 link), I mean cheap compared to an omega rolled staff). you should multi mod a staff. Before you do, you can just use a staff with the two mods you want (IMO you want Power Charge on Crit and the double damage/attack speed mods, but you can POB yourself and maybe you will come out with different results), whatever you regal onto it, and a craft. I was able to decently easily do T16s without the multimod and with only a 5 link. The staff should either be a maelstrom staff if you want 20% block, or a lathi as it will make your leap slam faster (I only realized this after I made my staff, or it would have been a lathi). You can use a crit staff if you want, but block helps you not die.

Lorweave got a nerf in 3.6, but it is still high damage and defensive. You could use a rare chest I guess, but this chest is still just so good. If you are on a budget a belly of the beast or corpse jack could also be decent choices.

These boots are tanky and give a lot of damage. They are not necessary, but are certainly a good pick up if you have the money.

Warlord's Mark on hit ring as I stated is real nice. I personally didn't use one until I could multi mod one. Multi modding the ring generally costs less than a Warlord's Mark on hit ring with similarly good stats. However, you may want to just regal craft one really fast, because blasphemy doesn't have as long range as one would like.

Xoph's blood gives a lot of damage, and saves you a passive point on the tree. I suggest it, but a rare can also do decently.

As with most of my builds you probably also want a stygian vice.

Further Discussion: You will need to get a decent amount of dex from items with this build. I chose to get it on gloves and ring. But a rare amulet or boots can also get some.

This chest is damage and life, but most importantly, it gives you enough leech to live through the damage you do to yourself.

To get a bunch of damage on the cheap (like 9-10 ex (including the 6 link), I mean cheap compared to an omega rolled staff). you should multi mod a staff. Before you do, you can just use a staff with the two mods you want (IMO you want Power Charge on Crit and the double damage/attack speed mods, but you can POB yourself and maybe you will come out with different results), whatever you regal onto it, and a craft. I was able to decently easily do T16s without the multimod and with only a 5 link. The staff should either be a maelstrom staff if you want 20% block, or a lathi as it will make your leap slam faster (I only realized this after I made my staff, or it would have been a lathi). You can use a crit staff if you want, but block helps you not die.

Warlord's Mark on hit ring as I stated is real nice. I personally didn't use one until I could multi mod one. Multi modding the ring generally costs less than a Warlord's Mark on hit ring with similarly good stats.

The Bubonic Trail boots give quite a bit of life and damage, especially since you can craft your own abyss jewels pretty easily with fossil crafting. Aberrant fossils can give a fat increase to chaos damage on every jewel (even the minion and attack based ones). This allows you to cheaply get a good set up of damage with good damage boots.

The amulet shown here is the one I used, and defiantly my weakest piece. The important part on it is the increase to leech recovery. The chest is enough to be positive on life gain even while full casting, but this amulet mod will actually make your life gain much better.

As with most builds a Stygian vice is also suggested.

Further Discussion: You will need to get a decent amount of dex from items with this build. I chose to get it on gloves and amulet mainly, but rings can also work. My rings are not loaded up with damage, but if you fully optimize your other gear you could put more damage on them.
I recommend the increased damage while leeching craft on amulet and gloves, as you are always leeching.