quickest way to do revenant from nothing

[elfin pecan]

Don't bother, you'll thank me later

[willow harbor]

I don't think there's a quicker way than playing the story and getting the tonic unlocked

play story to unlock tonics, craft uncommon onslaught gear tonic until you get rare onslaught weaponry tonic, craft rare tonic until you get legendary one for bittersweet.

should take 5 to go from uncommon to rare, then 5 to go from rare to legendary. up to rng if you get bittersweet tonic first or last though.

you will need to play onslaught salvation to get mats for legendary tonic.

dul incaru is probabaly still the way to farm, but I know they changed the rates a bit and kills are more worthwhile than before