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