PvE. it is a self-sufficent build, and that really has no place in the team-oriented pvp world. Plus, its a "tank", so would be useless in pvp where you want to kill people, not stand there while they wipe your team. Remember, people think, monsters dont, so there are often valid pve builds and strategies that have no place in pvp. I think its safe to say, a tank like this one that has no place in pvp.
I wouldn't use it anywhere. I mean, you'll stay alive, but won't do much else. Adding in Vow of Strength since you only have one attack skill wouldn't be a bad idea. You'll stay alive and do decent damage.
In PvP, you never apply superior runes. Ever. Having two plus two Major runes is suicide. You also have Pious Haste (it's in Mysticism), so there's no reason to ever use Flame Djinn's Haste OR Fire Magic.
Chilling Victory is kind of weak, since you're not making the most of it (you've only got burning from Heart of Fury). Mystic Sweep would have been more useful. Lastly, it has no elite skill.
Here's the generic one I use for pve when I don't know (or don't care) what mobs I'm going to be fighting.
(can't remember how the runes go, will just list the final attributes)
12 Scythe Mastery
12 Mysticism
10 Earth Prayers (pump it up to 12 with a rune if you want +4 regen per enchant on mystic regen)
[skill]mystic regeneration[/skill][skill]aura of thorns[/skill][skill]armor of sanctity[/skill][skill]eremite's zeal[/skill][skill]chilling victory[/skill][skill]heart of fury[/skill][skill]conviction[/skill][skill]resurrection signet[/skill]
Heart of fury for basic damage dealing, aura of thorns + armor of sanctity + conviction for tanking, mystig regen for healing, aura of thorns + eremite's zeal for energy and aoe cripple+bleed. Remember that you can use eremite's zeal on an enchant that's just about to end. Armor of sanctity and mystic regeneration both have pretty short durations.
There's a couple reasons why this is my "generic" build. It doesn't have an elite and I can swap out conviction or chilling victory without breaking any synergies, and it doesn't rely on a secondary class in case I want mending touch or something.
A good, safe rubric for making dervish builds for general play (mainly PvE):
Slot 1,2,3: Take three good attack skills. At least one of them should be [skill]Eremite's Attack[/skill] or [skill]Mystic Sweep[/skill] as they're fast followups and make for great damage per second. [skill]Victorious Sweep[/skill] is a cheap, spammable +damage attack, and is good in many situations. One of these may be an elite scythe attack.
Slot 4,5: Take an avatar, unless you've already taken an elite scythe attack. Balthazar (if you're tanking in PvE, never in PvP), Melandru's, Lyssa's, and Dwayna's are all worth consideration. Then take Eternal Aura to use this avatar eternally (unless in PvP, in which case take another utility attack, such as an interrupt or Wild Blow). If you've taken an elite scythe attack, take some defensive boost... the [skill]Aura of Thorns[/skill][skill]Armor of Sanctity[/skill] combo is a good one, as is [skill]Conviction[/skill].
Slot 6: Attack speed boost. [skill]Heart of Fury[/skill]
Slot 7: Self-heal... [skill]Mystic Regeneration[/skill] or one of the Interventions.
I would maybe switch out faithful with armor of sanctity. AoS is 5e and fast to cast if you want it for sandstorm, and AoS + weakened foes is almost always 0 physical damage.