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