RG_PankO's Onslaught Cheap Farming Build - Low Life RF Spork without Shavronne's Wrappings

You Kill everyone on Normal. You don't need neither the mana, neither the HP (obv.), the all ressistance is just 2% more then the normal nodes of +6% all res - IMO it is not worth it the obligation to go with that point with the +8% all res, because once you fix your gear you wont need it.
About Cruel - people tend to take Cast Speed, I didnt. It's 4%, while normal nodes are 3% Cast Speed. Following the logic for not taking the all resistance from Normal Difficulty I don't take the cast speed from Cruel, because it is an obligation, it's a skill point that I can not move from cast speed to crit or ES or whatever I want to. So I just let's say take 3% Cast Speed from the passive tree instead of that 4% from the bandit so can change it to whatever I want to later on.
About Merciless I take the Power Charge. It's something that you can not take anywhere else. You have direct access to 3 power charges on the passive tree, and actually in the build you do take them, but the one extra power charge is needed for the Void Battery unique wand. if you have that wand every single one power charge is really Important. With these Power Charges you gain extra Spell Dmg with that wand. So Having one more power charge really is a big deal, and endgame that's the ultimate wand/weapon for the sporker.

In order to gain the power charges you have to cast a skill that generates them yourself.
The trick is to use Ice Spear - becuas it has +600% chance to crit, at longer range, and you support that skill with LMP/GMP - so you have higher chance to hit something, and then you add the support gem Power Charge on Critical Strike.
So what happens is that you crit quite often, doing 0 DMG, because of the Ancestral Bond passive node, but you gain a pwoer charge that will increase your critical strike chance -> your totem's critical strike chance -> your DPS.

So... when I switched to low life I had 3.4k ES with 60% Fire res, haha.
That being said you can sustain your ES with even 2k ES, most probably.
If it's a good idea its totally different question ;)

Go for atleat 150 ES on your helmet, 350ish on Chest, 100 ES on your gloves and you will be fine.

Also dont go before 60ish lvl, finish the act 3 Merc quests then start farming Docks.

Springleaf gives you 6% Life Regenration. That is Huge.
With it I have 600 ES Regeneration, or so.
When you remove it to put your other shield you are losing that insane regeneration.

I found a 388 ES Shield that makes my ES up to 6.5k, with Springleaf I have 5k ES.
So with the 388 ES Shield I was barely able to sustain my ES. I was regeneratio naround 2 es a second.
The formula is like this:
You burn for 100% of your HP as fire dmg. So I have 700 HP and therefor I burn for 700 DMG per second, every second.
But I have 78 Fire ressitance therefore I burn actually for only 154 dmg per second (700 HP * (1 - 0.78) = 700 * 0.22 = 154)
And when you remove the springleafe you get just the regeneration from your Vitality Aura and the 1% from the Templar. That is 1% from templar and depending on the gem level, in my case, 1.4% So that is 2.4% Regeneration. 2.4% from 6.5k is 156. (Formula is 2.4% = 0.024 * 6500 = 156)
SO I DEGEN/Burn for 154 and I Regen for 156, the difference is Positive 2 - if I had for instance 6000 ES, not 6500, I was going to regen with the same Vitality level and the 1% from templar - 144, so I was going to DEGEN/Burn for 10 ES per second.
I hope I explain these formulas good enough so you can understand me.

And here are the numbers with my Springleaf on 5000 ES: I burn for 154 DMG, because of my 700 HP and 78 Fire ressistance, but I regen: 2.4(vitality + templar node) + 6%(Springleaf) = 8.4% * 5067 ES = 426 ES Regeneration per second.
And now we divide them to see the difference - 426 - 154 = 272 Actual Positive regeneration per second.

And here is an interesting fact. If you are getting DMG over time. And let's say that the fight that will bring you down to 0 ES from your 6500 ES, with the other shield, lasts 10 seconds, IF you/I were/was using Springleaf for these 10 seconds we were going to regenerate 10 * 272 ES = 2720 ES + the basic 5000 ES = 7700 ES!
So actually with Springleaf you have MORE ES then with a normal shield IF you dont get one shoted / burst damaged.

Well, a little bit long answer to your question but I hope I helped you a bit.

You need to blood magic auras on your HP in order to be on low life all the time.
Pretty much you have to buy one of two unqieus that grants you blood magic - the mask or the chest.
They are both... not that cheap. 10 chaos up to 1 ex, depending on the seller.
If you can't afford that you can always go BM gem, but you are losing one aura - you can put two 40% based auras on your HP if you have one of the two uniques, if you don't you will be able to put only one.
If you don't have the mask/chest you need BM gem + aura + as high lvl Reduced mana gem as possible - so you can have as much HP left as possible.
If you have one of the two uniques what you need is exactly 8lvl Reduced mana gem.
I've done the calculations, that's the highest lvl on the gem you have to go, and your HP will be on exactly 0.34 or so % - which is low life, but you are on as high HP as possible - one day you might lose all your ES and that HP saves you.
Another thingy that you can do is to put 3 auras on your HP, but you need as high as possible Reduced mana gem, and there is minimum lvl requirement of the gem for that - because if you put 3 auras of 40% reduced mana lvl 1-5 wont be enough for sure.