This is my first build guide so hopefully it isn't too poorly done.
This build is only for group play and is viable in both hardcore and softcore. This build is a pure support / tank build and you will not be doing any damage with it. However you will be buffing your parties damage greatly and therefore kill much faster. The main focus of this build is cooldown. With 81.55% cooldown you can have serenity up almost constantly and thus be basically invulnerable. You can also keep epiphany and inner sanctuary up constantly as well. Since spirit shouldn't be much of an issue you can replace epiphany with a heal, crowd control skill or another party buff but the extra 50% damage reduction form desert shroud helps make sure that you truly are invulnerable.
Crippling wave with the breaking wave rune increases damage against enemies hit with it by 10% for 3 seconds. Thus increasing your parties damage.
Cyclone Strike with the implosion rune pulls up to 16 enemies within 34 yards to you. This keeps the enemies on you so your party can focus on straight damage without having to worry about healing, kiting or anything else. Cyclone strike in conjunction with Sledge Fist make sure that the enemies are on you and not your party and Sledge Fist keeps them there.
Inner Sanctuary with the Forbidden Palace rune decreases damage taken by you and any party member inside the runic circle by 55% and also increases damage taken by enemies inside of it by 30%, as well as slows their movement speed by 80%. So with this one skill you are cutting damage in half for you and your party, giving a huge damage boost to your party and providing even more crowd control.
Serenity absorbs all incoming damage for 3 seconds and the ascension rune ups it to 4 seconds and with enough cooldown you can basically keep it up constantly but even if you don't recast it immediately after 4 seconds then your life regen, armor, all res and other skills will still keep you alive and tanking without a problem.
Epiphany with the desert shroud rune ensures that you won't have any problems with running out of spirit and also reduces damage taken by 50%. You can replace Epiphany with another skill but I highly recommend keeping it since between it, serenity and inner sanctuary you will be invulnerable and able to tank any and everything easily.
Finally I use Mantra of Conviction with the Overawe rune to increase the damage my party is doing. The passive of Mantra of Conviction alone causes enemies within 30 yards of you to take 10% more damage, and the Overawe rune ups that to 16% while active the damage bonus is increased an extra 10%. You can swap this out for another mantra that may be more beneficial to your party. Of course with the Inna's set you can swap it out all together for an entirely different skill to heal, cc or buff. I just like adding the extra damage to my party for faster clear speeds and since surviving won't be an issue with this build then the extra damage bonus is a huge plus.
If you are able to obtain enough cooldown without beacon of ytar then feel free to switch it out for another passive, it is just more obtainable using it and allows you to focus on other stats on some of your gear. Sixth sense can be switched out as well.
SPECIAL NOTE FOR XBOX 360 AND PS3 PLAYERS
If you are a console player especially on Xbox 360 or PS3 then you can use this build as well except with a few changes since some of the passives are different and you don't have access to some of the items or any legendary gems. On those two systems you will want to use Aughilds helm and bracers for the 3 piece Aughilds bonus. Swap out crippling wave for deadly reach with the rune that adds 40% armor after the third strike. Also if you have the needed Inna's set pieces then definitely swap out the Mantra for Exploding Palm with the flesh is weak rune which will make enemies hit with Exploding Palm take an extra 20% damage. Also on those two systems Exploding Palm deals half of the tagged enemies total life as damage to all nearby enemies when they explode with Exploding Palm on them. T6 rift guardians have about 5 billion life. Thus if you kill a T6 rift guardian while Exploding palm is active on them then they will explode dealing 2.5 BILLION damage to all nearby enemies. Mobs literally melt away using this skill on console and it makes killing a whole lot easier and faster. Suck an elite pack in while battling a rift guardian, tag every enemy around with exploding palm and once one dies they pretty much all die. Exploding Palm is too good not to use on those two systems and the damage it causes is insane. For passives harmony replaced one with everything so just use it and stack the same single elemental resistance on all of your gear for extremely high all res. You won't be able to get the benefit of Leoric's cowns affix since it doesn't exist on those two systems so beacon of Ytar is a must to get higher cdr.