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