well, imo erawan is a better armor for us since it has 25%vit bonus and we're full vit spec. May or may not add up to more life than dragonheart. drink a potion too for jday. if you're not comfortable letting your life get low just keep it up with pots. pots + eagle + tb should be enough to keep you full. then when one of the bosses spawns run up to him and burn him down with RoL. You should have at least 80k per second damage with it so it should take 3-4 seconds at most.
We're not really trying to tank jitan's guard towers. just force them to walk through the hallway and therefore through our ring of light deathtrap. lay down your RoLs and get out of there while they all die.