Here is the full list of all 22 Merchants of Kaidan achievements.
Complete 50 transactions within 50 days
Within 50 days multiply your wealth twofold
Collect 50 diamonds
Collect 10 000 trigons
Collect 16 different items
Kill your first monster
Retain maximum luck for 25 days in a row
Retain minimal luck for 25 days in a row
Visit all mines within 60 days
Take a loss on 3 transactions conducted in 3 different locations visited in a row
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
Complete 3 transactions in all 3 regions within 25 days
Visit all the sea ports within 80 days
Travel with the airship 10 times in a row
Buy 100 cards in the shrines
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