This fight was big problems for my 5x ele shamans. Tried it at 60, 62 and just got toasted by Nazan's firebreath. I eventually beat it at 64 -- but only after using a cheap trick I ran across on the forum.

I'm not sure if this is common knowledge or not, but I found it really helpful and probably would have had to wait till I had access to Earth Elementals or a tank to complete it.

The trick is to pull the first two mobs (that start the event) at the bottom of the ramp all the way to the top of the ramp with your main character. Have the other four guys waiting at the top of the ramp with totems or whatever; if you run too far with your main the 2 mobs your pulling will reset. Pull them just far enough to get everyone in lightning bolt range. Once you take them out you'll notice that only Nazan is aggroed. Vazruden isn't, he just waits in the middle of the platform for you to attack him. Don't, just dps Nazan.

Drop grounding totems and get away from them. Nazan will fire blast the grounding totems but the AOE damage can still get you (which is why I didn't think they worked here at first). DPS Nazan and at about 30% he will land. Trigger trinkets, elemental mastery, or whatever you have in your bag of tricks, and go all out. Hopefully he dies before you. If he doesn't you might have to reset the instance and start all over again -- not sure about this though.

The funny part is Vazruden will still be standing in the middle of the platform after you kill Nazan. Just finish him off whenever your ready. I was able to finally complete the 2 Ramparts quests and even loot the chest (I figured it would have bugged out or whatever, but it was fine)... I Wonder if this method works for the heroic mode?