Here is the full list of all 22 Thorne - there are Death Merchants achievements.
Find out about Eldyn's suicide
Save Matthias from Ray's Gang
Slay the Abyss Mermaid
Karma is a...
Find the Fallen King's Crown at Fire Isle
Defeat Ray at Gang's Hideout
Find the accessory near Simeone's Cave
Find the Rowens near McArthur State
Speak with the Death Merchant
Take the Lycan's contract
Convince Skillet into releasing you
Take the blame for Idegert's murder
Slay the Wyverns at the Lighthouse
Speak to Layla at Hollow Lake's bridge
Face the Lycan at Hollow Lake
Meet McArthur at the Estate
Destroy the nests at the Goblin Cave
Defeat the Revenant
Speak to Faida at Ocean View
Speak with Layla at Hollow Lake
Bring Olav the antidote
Defeat Ray at Dead End