Hey, I seen a few posts around that said AR/Blood isn?t viable for this encounter. I want to disprove that and post my experience with this as an AR/Blood healer.
What is the Gatekeeper
After you have run all the dungeons on elite mode (there are 8 of them), you are ready to face the Gatekeeper for access to Nightmare Mode. You won?t get a quest to face him, you just have to know (or have a friend that knows).
To get to him, take the left portal from Agartha main entrance rather than the usual right portal.
What gear do you need?
The gear I had was all ql10 blues from running a bunch of elite dungeons. This put me around close to 2.5k heal rating. You don?t need to put on any tanking/HP talisman for this, if you screw up, its one shot. Stack for as much heal rating as possible
What build you need?
You have to pick up Tranfuse and Abuse from Blood Magic Chirurgia line. Once you picked that ability up, this fight becomes fairly simple. None of your group heal abilities (i.e. Cold Blooded) works here so don?t even bother putting them on the Hotbar. Platoon is nice to heal yourself if you get the Blood Offering debuff.
This the build I used
Blood Shield (resource builder)
The Scarlet Arts
Shot of Anima
Tranfuse and Abuse
Lock & Load/Platoon
Tip: Go to your interface options and turn on healthbars ? this will make the later stage of the fight alooooooot easier.
For me, I used mostly just Anima Shot and Shot of Anima whenever it was up. It was enough to keep the friend alive. If the friend fell off below 3k HP I used Scarlet Arts to topped him up. You won?t be able to hit the Gatekeeper for much but that doesn?t mean you can?t heal. The main heal component of your anima shot still works great.
There are several mechanic to this fight that may not be obvious at first. If you have issues with some mechanics, here is a walkthrough for that fight.
Good luck, its a fun fight!