Here is the full list of all 38 Dark Souls II achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Earn all achievements
Learn all sorceries
Increase the population of Majula
Learn all gestures
Learn all miracles
Learn all pyromancies
Learn all hexes
Discover the abysmal covenant
Discover the covenant of the protectors
Discover the covenant of the bloodthirsty
Discover an ancient covenant
Discover the clangorous covenant
Inherit Benhart of Jugo's equipment
Inherit Laddersmith Gilligan's equipment
Inherit Steady Hand McDuff's equipment
Light all flames on the map in Majula
Discover the covenant of the fittest
See the ending
Defeat Vendrick
Inherit Captain Drummond's equipment
Acquire Ashen Mist Heart
Inherit equipment from Lucatiel of Mirrah
Acquire the King's Ring
Reinforce a weapon to its limit
Defeat Looking Glass Knight
Die for the first time
Light the primal bonfire in Brightstone Cove Tseldora
Max-out devotion to covenant
Inherit equipment from the head of Vengarl
Give Rosabeth of Melfia something to wear
Light the primal bonfire in the Iron Keep
Discover the covenant of the meek
Discover a most brilliant covenant
Light the primal bonfire in the Black Gulch
Discover the covenant of rodents
Light the primal bonfire in Sinner's Rise
Defeat the Last Giant
Reclaim flesh and set out as an Undead