Is it involved Oathkeeper mastery and the new Guardian of Empyrion pet?
Nah, GoE is a player scaling pet so it’s not a pet per se. The strongest pet build has always been and most likely always will be one of the Beastcaller conjurers (shaman/occultist). Which one? We’re still waiting… Head of Preatorian Pet Department fell somewhat silent as of late…
It may sound funny to you but i completely missed the fact this pet scales with the player 
How about the new pets they’ve added to FG? Are there any noteable to mention?
Would be interesting if a new pet build arises. My very first char (main char still) is a classic pet conjurer. He grew and changed over time with some changes, but he is stronger than ever as far as i can tell. my char has 14k health and resists all capped, which is not bad for a caster that doesnt even get attakced for most of the time. hungering void and focusing on lightning damage for my pets is still extremely strong and fun. even the 2 “nerfs” that happened to Bound Wraith and the amulet that did summon 2 familiars (i think bysmiels it was)… doesnt matter. It feels like my pets are destroying everything even a bit faster than before. Also they are very tanky, and i like that. Thats why i still prefer Conjurer over Cabalist. My tankiest pet has almost 300k health here, which is a crap ton.
As far as i’m concerned, there is no reason for me to Change anything at all, especially not to acid damage, since lightning fits conjurer more imo, acid should be great for cabalist (dunno). After all, what else do you Need as a Petmaster when you can have the primal Spirit up all the time as well? 
I think Maya’s double bird conjurer is one of the strongest pet builds at the moment. It can easily do both FG superbosses and farm Crucible 150-170 and SR 75-76.
Quoted For Truth!
It just got even stronger btw. 2 min flat Crate Superboss kill 
Im sure its amazing, i dont like the fact it uses just one mastery. I like my build to be as much varied as possible.
He is talking about this: http://grimdawn.com/forums/showthread.php?t=81004
It doesn’t use just one mastery. That one is http://grimdawn.com/forums/showthread.php?t=82637
ya if you can get the new fg set for 2x raven you can kill things just as fast as the old 2x raven build conjurer, but ya i think either the 2x briarthorn or 2x raven build is prob the best still. You can prob add chillmane if you play the 2x brairthorn build. Sadly you can no longer just use the amulet for 2x raven as that been nerfed and have to use the new fg set for 2x raven.
Oh, thank you for sharing this Maya 
Ive been looking for a pet build, ill be starting one today and ill follow your build.
Which of the two do you recommend? (Forget what i said earlier, im interested on your insight).
The Pet Occultist was more about me wanting to see if I could do it.
The Pet Conjurer is far easier to play and stronger too. Also easier to level up compared to doing a solo mastery.
So, I’d recommend the Conjurer over the Occultist unless you want a Single mastery build.
Cool!
How come you didnt assign your hellhound/briarthorn with any skills?
They die too fast against FG’s superbosses. But you can assign Elemental Storm to one of them (or the dirge pet) instead of Wind Devils. I would actually recommend that in the Crucible and SR. I just keep it bound to Wind Devils so that I have constant RR against the likes of the Crate Secret Boss.
But if they die too fast, whats the main source of damage in this build? The birds?
Yes, Birds carry the build. The rest are just there to act as fodder and distraction.
Oh i see… Interesting.
Its been a long while since ive last used birds. Their attacks always seemed so slow compared to the rest of the pets, i couldnt understand how can they act as a carry role in a pet build in general.
Ive started level 1 character on ultimate, im level 29 and im on the second quest in act 1 (lol).
I gotta say im kinda struggling but i suppose its alright, this suppose to be hard. I hope ill manage to push myself above 50 so i could wear some of the better pet items that i stock in my chest.
It has to do with their projectiles “Shotgunning” (that is if you make all 5 hit on a single enemy it does 5x dmg per Familiar) + nearly max-capped Storm Spirit & Lightning Strike.
And when you factor in all the bonus dmg and additional flat dmg from devotions + items and conversion of all physical dmg into Elemental, you quickly rack up the numbers.
I do agree that speed can be a bit slow early on, but endgame it gets to respectable amounts. You could still go for more if you change certain things, but I prefer being immortal (or nearly immortal) to faster killing
But how does it work against those two ridiculous super bosses? My pets get smashed within 10-15 seconds everytime. If you have 2 Familiars left that dont draw aggro, i assume you just kite forever and the Ravens cast their bolts? I jsut can say that this Crate Superboss always ignores my pets and kills me instant.
Edit: Why youre not using a Voidmancers Cord as well?
Still: Why no Voidmancers cord? That damage buff should be immense or am i missing something here?
But i will definitely try that out since i still miss the two birds anyway. Just ba di have to give up so many cool beasts for a new set instead of equipping one amulet only.