[C] [N/Me] Blood Hunger

Everyone knows that lifesteal necros can own it up in the Random Arena. Well, the new elite Vampiric Spirit* adds a little lifesteal to every spell. Nothing too complex here.

Blood Magic: 12+3+1
Soul Reaping: 6+1
Curses: 6+1
Inspiration: 10

Vampiric Spirit, 5e 1 5s elite*
For 21 seconds, your Spells cost 3 more Energy, but whenever you cast a Spell you steal up to 53 Health from one nearby foe.
Dark Pact, 5e 1 2s
Sacrifice 10% Health and deal 51 shadow damage to target foe.
Blood Drinker, 5e 2 8s
If your Health is above 50%, you begin Bleeding for 10 seconds. Steal up to 68 Health from target foe.
Blood Renewal, 5e 1 10s
Sacrifice 25% maximum Health. For 10 seconds, you gain +6 Health regeneration. When Blood Renewal ends, you gain 200 Health.
Channeling, 5e 1 15s
For 40 seconds, whenever you cast a spell, you gain 1 Energy from each foe in the area.
Power Drain, 5e 1/4 25s
If target foe is casting a spell, the spell is interrupted and you gain 21 Energy
Malaise, 5e 2 2s
For 19 seconds, target foe suffers Energy degeneration of -2 and you suffer Health degeneration of -2. Malaise ends if target foe's Energy reaches 0.
Rez Sig, - 3 -
Resurrect target ally with full health and 25% energy.

Basically, Vampiric Spirit means you get a cheap semi-untargetted Vamp Gaze with the purchase of any spell. I'm not clear on whether it works like Divine Boon, and takes another 3 energy after the spell is cast, or if all the 5e spells actually require 8e. Nonetheless, it brings a lot of pain for not so great a cost, and is a pleasantly flexible enchantment.
Dark Pact is the workhorse damage dealer of this build. For a sacrifice of 10% of your health (usually 45 health from 455 total) it deals 51 shadow damage. The 53 point lifesteal slightly exceeds the amount of life you sacrifice, and more than doubles the damage done.
Blood Drinker refreshes every 8 seconds, and is the big direct heal of this build. At 16 blood, it steals 68 health, and with the extra 53 that's a total of 121 health gained.
Blood Renewal helps with degen, and is another big heal (though one you have to wait for). The sacrifice of 25% health is again offset by the 53 pt lifesteal that accompanies it, effectively reducing the sacrifice by half. Blood Renewal -> Blood Drinker would act as a net heal (53+121 - [455 * 0.25] = 62) while adding 3 regen (assuming Blood Drinker triggered the bleeding), and healing for another 200 in 10 seconds.
Channeling is some passive energy management, and helps to pay off some of the added cost of Vampiric Spirit. Because you already have to be 'nearby' for Vampiric Spirit to activate, there should always be at least one foe 'in the area' when you cast spells.
Power Drain is active energy management, netting 16e on a successful interrupt. This build requires a lot of energy to keep chugging, and Power Drain is here to help.
Malaise gives us something to do with all that excess health that's flowing in. Usually the 2 degen from each instance of malaise you cast is a problem, but with the amount of health being stolen by this build, it should have zero problem keeping up. This adds a little depth to the build, applying some unfocused energy denial to the enemy team.
Rez Sig because this is a Random/Team arena build.

The biggest problem for this build will definitely be keeping its energy up. Channeling might not have enough to work with in a 4v4 arena, and I might look for other e-management options. Soul Reaping is at 7, which is nothing exceptional- but Soul Reap rarely brings in significant energy in 4v4 either.
This build can be taken apart by an interrupt ranger, as most spells are 1 second casts and a few (blood drinker, malaise) are 2. Malaise em and hide behind scenery.