BEHOLD A PALE HORSE AND UPON HIM RODE [Saryn]

This build makes Arbitrations and SP trivial.

Turn on Gloom (In your 2)
Cast Spores (1)
Cast Toxic Lash (3)
Watch it spread as you walk around virtually invincible.

The amount of Forma required can be reduced by using 1 or 2 Umbra Forma. Totally up to the user if using Umbra Forma here is worth it but its an option.

Shield gating can be easy with a dragon key here but the tankiness you already have honestly makes gating unnecessary most of the time. I personally do not gate with this build.

[Physique] can be swapped out for [Growing Power] but will cost a stance Forma

[Hunter Adrenaline] only works if you arent shield gating and can probably be swapped out for something else if you do gate. Personally I dont shield gate and the return ensures Gloom stays active in the most thick of battles as well as enabling multiple uses of Miasma (4) as a way to rapidly drop the amount of mobs affected by Gloom. In other words... If your energy is dropping to fast, spend the energy to pop Miasma and stabilize the energy consumption.

I also recommend Zenurik as Wellspring can turn things around if you find yourself in an energy drought.

It is IMPORTANT to watch your incoming Energy and THE AMOUNT OF MOBS IN THE AREA.
I can not stress enough the importance of watching that because you can easily go from full energy to 0 in seconds if you are not gaining energy and you have a large amount of mobs trapped in gloom. It will melt your energy bar and then you die....... ENERGY IS LIFE and is much more important than your actual HP bar.

Im sure this build can be tweaked and alot of people may have opinions on this build but Ive been running this build for over a month now as my main and I can literally just cast 1, 2 & 3 and then from then on just drop 1 every once in awhile on groups not yet infected and tank EVERYTHING as I walk around just watching everything die.

Actually fighting is optional

I also run [Healing Return] on my melee but honestly thats probably Overkill.

The amount of HP recovered from just a few infected mobs means you can be nuked for 99% of your hp and the bar will be full again in a fraction of a second. The only way to die is to be nuked for your entire HP pool or just totally go AFK for like 5 minutes and do nothing to maintain the plague.

Gloom is important to your survival, Without it you die. It gets easy to forget that because youll feel invincible but if you lose all energy and ultimately gloom while you are in combat you WILL DIE INSTANTLY.

With that said though this build is super easy, super tanky and super killy.... Have Fun