Achievements:
Easy "Perfectionist" achievement or trophy:
A quest is registered every time the message "Quest success" appears, including
when you reload to farm the same quest repeatedly. One good quest to farm occurs
early in the game, as you first leave Crab Coast after joining with Bones.
Visiting each island for the first time counts as a successful quest. Visiting
each island in succession counts as six quests. You can reach 300 by doing this,
but will require some time as it needs 50 saved game reloads and the time to
complete each trip to the six ports. Another location to increment the completed
quest total is in Calador, at the Citadel of the Demon Hunters. Save the game
before entering the Citadel for the first time. Then, enter it and it will count
as a successful quest. Go to the small shop to the left inside the large entrance hall and talk Connor until all responses are exhausted. This will give and complete four quests in quick succession. Reload the saved game and repeat the process.
Freddie's Shackles legendary item ("Fog Island" DLC):
Talk to Bones to get to Fog Island. The Freddie's Shackles legendary item can be found at a small village. It gives a +10% Glory bonus.