I play a Demon Hunter with high DPS but average defense. I usually rely on Caltrops, Vault and the Templar to evade enemies, but I can usually take a few strikes if need be.
However, Rakanoth, the melee boss towards the beginning of act 4 (in the Library of Fate, just off the Gardens of Hope 1st Tier waypoint), is really giving me trouble. He teleports right on me and take away most of my life with one blow, and he does that attack at a higher frequency than I can heal completely, even if I run with powerful potions and Preparation with the healing rune.
What build / strategy can I take to help me defeat it? I'd prefer something which does not require me to change my entire gear.
Difficulty is nightmare, but I have a feeling this question could also apply to hell and inferno.