On the run we did last night, that's exactly what we figured out. After starting the fight, our RDM proceeded to Grav the thing and kite it around a log, which is now our favorite log. It could barely move, much less get close enough to Bad Breath us, and the RDM and the RNGs nuked/Jishnu'd it down fairly easy enough. Vallation with Unda runes seemed to lessen the DoT. Dropped some lixirs and an Eschan Breastplate.
Next was a bright red golem, which I also used Unda against...good thing, too, as it liked to spam Fire VI and various other toasty nukes. Crystal Weapon hurt a few melee, I didn't notice it much until I let Phalanx drop. At 1% it oneshot me somehow; I'm not really sure what happened there. Dies to DNC dark chains, unfortunately necessitating curebombing said DNC immediately afterward.
Next pop was a wyvern mob that also used fire-based attacks, and it was pretty weak overall. I think this guy dropped the Vanya Robe, immediately causing every mage in the party to drop everything and lot. Alas, I lost, but it was a easy win.
Then the wivre. This thing. Avoidance Down SUCKS, and by sucks I mean ".. Yeah I'm dead because I can't parry this sh!t". Boiling Blood should probably get dispelled ASAP, as should Granite Skin, but at that point our RDM had logged and I forgot to call up Koru. We came back in, deciding to try it with a pld, with similar results re: " GDI I can't block this isht and even PDT at cap isn't helping". Short of pulling a mythic out of thin air, neither of us are going to mitigate anything more.
Anyone have a good strategy for this guy? I want revenge.