Witch Doctor - Spirit Doc

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As a resource, mana hasn't changed much since Diablo 2 compared to other classes. Mana is the slowest regenerating resource by the time you reach the endgame, but it also manages to raise in how much you can reserve as you level. To follow this, most of the Witch Doctor's skills will also increase in cost, and with the omission of mana pots this time around, different tactics have to be taken this time around to make sure your blue globe isn't dry. One such solution is by focusing in the spirit school:

Active Skills

-The Spirit is Willing

A pretty no-nonsense nuke here, Spirit Barrage does great damage for a very cheap cost. A Golden Runestone here adds some mana return after your done bombarding the target.

-Draining Spirit

Extremely potent damage over time spell thats pretty easy to keep going considering it will find a new target after it's first is dead. Better yet, with another Golden rune, this spell will be better than free, coming out with a net gain of 300% mana cost after the dot has run it's entire duration. Great with packs of enemies, no need to spam on bosses and uniques though.

-Vengeful Spirit

This one on it's own is a great self buff that will help empower your main damage spells. Alabaster sweetens the deal by making the 5 afflicted enemies take 250% weapon damage, meaning you can get in with some of your enhanced physical damage if you feel like or let your party start wailing on your foes like crazy.

-Ruthless Terror

Fantastic defensive cooldown that can really get you out a tight jam. If your feeling low on mana, you can set this up for some major returns from your Gold by getting into a pack and send them scuttling in fear. Bonus points for Soul Harvesting first.

-Healing Journey

Another great defensive cooldown that will let you get in/out of a large group of enemies. An Alabaster here will restore almost half your life if you can let it run it's full duration. The cooldown period is only 15 seconds, so make use of the healing whenever you can.

-Paranoia

Mass Confusion on it's own can be a real game changer, cutting your foe's forces in half and giving you some buddies for a little while. Add in the 80% increased damage buff and you can absolutely decimate a large group of foes. This will also work great for Bosses and Uniques, if only for the extra damage

Passive Skills

-Rush of Essence

The passive that makes a spirit doctor, by spacing out and rotating your skills around, you'll be passively regenerating twice the amount spent on each spell over the course of 10 seconds. Granted some of the skills (even ones listed on the passive) don't actually have a mana cost, but between the ones that do and the Golden Runestones socketed into half your skills, you should be swimming in mana...

-Pierce the Veil

...maybe even too much mana, but thats where Pierce comes in. 20% damage for 30% cost is a real bargain considering most of your skills will be giving you a net gain of mana anyway. Pretty much gravy for this build

-Vision Quest

The last bit for mana management. With the Runes set up in this particular fashion, your looking at 2 15-second cooldowns, a 20-second cooldown, and a 60-second cooldown. Opening up with Mass Confusion, followed by as many of your other long cooldowns as possible will put extra damage on the board, top off your health, fear a lot of foes, and then start up the 300% regeneration phase. Once you've got this going, feel free to start haunting and barraging as much as you can before Harvest or Walk come off cooldown.

Lots of room for tweaking here, as some of the mana return may be overkill or underwhelming depending on your playstyle. Add more Golden Runestones if you find yourself going dry, otherwise swap some out for more interesting abilities. If you end up dropping skills with long cooldowns, it will be to your benefit to swap out Vision Quest for something else, such as Spiritual Attunement. Another possibility is throwing in a skill to drain excess mana, such as Firebats or Wall of Zombies (great with fear).

Barbarian - Epic Cooldowns

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Many of the classes this time around for Diablo now feature many more skills that trade long cooldowns for extremely powerful effects, usually meant to be used in emergency situations. The Barbarian in particular features a diverse trinity of varied yet ultimately destructive high level abilities that can greatly shift the shape of any conflict. Utilizing particular passives to aid in cooldown reduction and fury generation, you too can shake the very foundations of Sanctuary:

Active Skills

-Unleashed

As a Fury generator, Bash unruned is probably second only to Frenzy. By throwing in a Golden Rune, you'll be able to top off Fury very easily, while dishing out some great damage to boot. Handy considering you'll be going through that orange globe like candy.

-Invigorate

An Alabaster here not only makes you more durable, but the rest of your party as well. The final effect is a mixture reminiscent of a D2 Barb's Iron Skin and Battle Orders rolled together in one package. Better yet, you'll see a nice buff to passive life regeneration, as well as a solid 30 Fury to boot.

-Smash

Excellent single target nuke at a pretty cheap price, Hammer is great for dealing with bosses and uniques. If you manage to sync this up with Wrath, you should see a plethora of crits off this bad boy.

-The Mountain's Call

The first in our trifecta of super skills, Earthquake is going to be your main way of taking out large packs of enemies. For 40 Fury and a 20 second cooldown, you'll be able to dish out what is essentially 14 weapon swings to all enemies in a 15 yard range over the course of 8 seconds (dunno if I put enough numbers in that last sentence).

-Thrive on Chaos

An all around awesome self-buff for the Barb, Wrath will let dish out and take more damage over the course of it's duration. With a Golden Rune slotted in here, every Bash will add at least a second to the duration. War Cry during this skill three seconds. Like the Hammer, it's best usage is going to be on Bosses and Uniques. Expect about a minute on average for the cooldown when all is said and done.

-Duty to the Clan

Everybody remember the Rite of Passage quest from Act 5 of D2? It's like that except these bruisers are on your side now! During the duration of this ability, you'll basically be quadrupling your weapon damage, extra nice if your beating down a lone target. Boon plus Gold will mean the extra Barbs are up nearly all the time, the dead zone lasting only 5 seconds. Assuming they also benefit from the effects of your War Cry as well, they should be able to hold their own with ease.

Passive Skills

-Boon of Bul-Kathos

This alongside all your runed cooldown reduction is going to make you an explosive powerhouse. Keep your barbs up, quake in large packs of enemies, and Wrath when you see a boss.

-Unforgiving

This is a very heavy Fury spending build. Your going to have to top off your resources in as expedient a fashion as you possibly can in order to quake, wrath and call. Being able to carry over spare Fury from your last engagement, as well as passively generate more Fury between fights is going to go a long ways in making this possible.

-Animosity

The other great Fury passive, Animosity is going to make you much quicker in not only getting your big skills going, but also sustaining Wrath's duration.

The first 3 skills in the build are actually very modular when it comes to keeping the spirit of this build intact. If your having trouble with AoE, you can drop the Hammer or it's rune for something with a little more reach. Switching Hammer for another Fury generator with a long Cooldown is probably the best solution if your having trouble getting topped off, that or throwing a Gold into War Cry. Mix and match to find what works best for you.