Here is the full list of all 22 Merchants of Kaidan achievements.
Buy 100 cards in the shrines
Travel with the airship 10 times in a row
Complete 50 transactions within 50 days
Visit all the sea ports within 80 days
Collect 16 different items
Complete 3 transactions in all 3 regions within 25 days
Collect 10 000 trigons
Take a loss on 3 transactions conducted in 3 different locations visited in a row
Retain maximum luck for 25 days in a row
Visit all mines within 60 days
Complete 50 quests
Complete 100 quests
Collect 1 000 000 trigons
Become an owner of 3 operating mines
Become an owner of 3 operating vineries
Within 50 days multiply your wealth twofold
Collect 50 diamonds
Retain minimal luck for 25 days in a row
Buy and sell each of the available goods at least once
Visit all the locations
Obtain the highest rank in the Dark Council - the golden chain
Kill your first monster