Agnerod Ball lightning Build help

https://poebuilder.com/character/AAAAAgMA37CCEI-mRKtVriycEFh2EV8q6-QEB3RVrJgRD36v3YzZX-ASjRn318NtXGuESIIeFLBMLXvXj_rsGMHFiEIvb9kTcLvyHWSd6_V_xtD1QZYFQj1fUlOXlUyzl_RtGRFQNbmnK4CkVdZk5xcv-tIdFI9Gm6FCoySwtvr3po5kWK5epRNxjHa3McAaZp6QVRo4gpvsOJ4873w8BZo72fzAZp_fi4zAmgmq-d3Mt3GF1XWxQuGIRnG0DJMnHNwdqncHhxOcpG-egwkNfOq6RtdXKdWm7TzGnhB_DH2Cxyj6V8mus19q2-dHBtDQwwm5kw==

Concerns:
Gems – Should I take faster casting or added lightning damage with Ball lightning?
Gear – Not sure which piece of gear to take on chest, also don’t know if those unique rings are a wasted slot.

Bandits: kill/ cast speed/ kill

Links:
Vaal mask – Reduced mana – haste – Discipline – Wrath
Agner Rod – Ball lightning – GMP – Spell echo – Added lightning damage(or faster casting) – Lightning penetration – increased area of effect
Chest – Blood magic – Reduced mana – Empower – Clarity – Herald of thunder – Herald of Ash
Gloves – Conductivity – faster casting – reduced mana - empower
Boots – CWDT – Enduring cry – Immortal call – Increased duration



Chest: Carcass jack or Shavronnes wrappings or atziri’s splendor or rare?
Necklace : rare necklace
Boots: Rainbow stride or Rare
Weapon: Agnerod East Imperial staff
Belt: Doryani’s invitation
Ring: Gifts from Above or rare?
Ring: valako’s sign or Rare
Gloves: Atziri’s acuity or Rare
Helm: Vaal mask

Firstly, in any low life build you are required to take either solaris lorica, or shavronne's wrappings in your chest slot. There is really no other option.

There are a few things I see in your skill tree that I would personally change.

First, you take a large number of crit nodes but skip right over all the power charges. Power charges give you 50% global crit each, so for any crit build they are a must.

Secondly, life nodes are a waste in a low life build, unless you plan to use your life pool to cast your spells. In this case they are not useful.

Third, I assume since you are running wrath, this is a build for when act 4 comes out, in which case buff effect in the tree is being removed.

I would use something similar to this

You get more energy shield and a lot more crit.

As for your gem links, the first thing to note is that the unique vaal mask gives 50% reduced mana cost of skills, which does NOT affect aura reservation. Putting your haste discipline and wrath in the unique helmet does not reduce the amount of mana they reserve, so if you are dead set on using the vaal mask, you might as well put your curse 4link in it to get some use out of the reduced mana cost. Otherwise a high energy shield rare will be better.

in my opinion ball lightning is strongest with only one projectile. Not only does GMP reduce the damage of ball lightning, it also even further reduces it through gem slot opportunity cost. Ball lightning does not "shotgun" or stack on top of eachother, only one ball can hit each enemy at a time. This makes GMP really bad for ball lightning as a main damage skill, and only really useful with curse on hit.

For your main ball lightning setup, I would recommend
1. Ball lightning
2. Spell echo
3. Lightning penetration
4. Power charge on critical
5. Crit multi / faster casting (depending on your crit chance. Higher crit chance makes crit multi more effective)
6. empower / crit multi / faster casting

For a crit ball lightning spec faster casting will be better than added lightning because you want to get your shock up on the target asap, so you want the maximum number of chances to crit per second.
In a non-crit spec usually quality added lightning will be better because it gives chance to shock.

I would also recommend taking the alira power charge in merciless.

Gifts from above is a great ring if you are planning on doing some magic finding, but it looks like your build will struggle with getting capped resistances since a large number of your armor slots are dedicated to unique items. If you have near perfect rare gear you might want to run gifts from above.

Valako's sign is a large damage boost for a build like this, but again I would say it depends on your other gear. Capping resistances will always come first.