Problems with Tihark Orchard Mish

I am a Derv/Warr trying to do the Tihark Orch. mish. It is the solo one in Vabbi. I cannot beat those blasted harpies. I have tried the following builds.

[skill]Vital Boon[/skill][skill]Heart of Fury[/skill][skill]Zealous Renewal[/skill][skill]Eremites Attack[/skill][skill]Mystic Sweep[/skill][skill]Reapers Sweep[/skill]{E}[skill]Signet of Pious Light[/skill][skill]Resurrection Signet[/skill]

And an Avatar of Lyssa Build:

[skill]Vital Boon[/skill][skill]Heart of Fury[/skill][skill]Eternal Aura[/skill][skill]Eremites Attack[/skill][skill]Mystic Sweep[/skill][skill]Avatar of Lyssa[/skill]{E}[skill]Signet of Pious Light[/skill][skill]Resurrection Signet[/skill]

I know I don't need the rez so I will swap that out. I was thinking of using [skill]Mystic Vigor[/skill]. Any thoughts including changing my secondary are appreciated.

I don't recall the harpies being a problem at all for me, so I can't tell what you're doing wrong. If you find yourself being attacked by all the harpies at once, back off a bit and let the guards take out most of them. It's easy to finish them off after that.

bring a long bow and pull the harpies to you. keep back-strolling once they are aggroed until you are in the ranger of the guards so they can help you out. doing this will allow you a much safer, easier completion on the mission. BUT, you have to be quick, if you wait too long, the harpies can possibly kill off your support (if they're already aggroed into a dif set of guards), and then you'll be pooped :P

[skill]Ebon Dust Aura[/skill], perhaps?

I'm R10 Norn so I just ran UB, but I'm Monk primary.

Just stay back and let them aggro on the guards, when they are fighting the guards join in yourself. It should be easy this way.

I guess you meant hard mode there, coz normal mode shouldnt be a problem at all, even to a wanding wammo...
I think the suggestion of Ebon Dust Aura is a pretty well idea. You might wanna take some condition pressure like poison and bleeding so they will just degen to death while you pretty much tank them with your blinding skill and your ... mystic regeneration. I would suggest an ebon bow. D/R and then take poison tip signet or apply poison with screaming shot and a disruption shot for any healing they have like heal signet (dont know if they have it but). You just keep them blinded and they will degen to death.