You will need to be a mage which has Spellsteal.
There are mobs at the Dusklight Bridge in Townlong Steppes called
They have a magic buff called Timberhusk that
reduces damage by 80% and the buff stacks.
If you go there as a mage and
spell steal as many stacks as you can you will take next to no damage.
Spell steal caps at 2 minutes so you only have 2 minutes after stealing
the first stack though you should only need 4-5 stacks to reduce any
damage to single digit numbers.