Here is the full list of all 78 Within the Blade achievements.
Complete the game (permadeath mode)
Complete all tasks in 2 act
Make 500 horizontal cuts
Make 500 diagonal cuts
Behead 500 enemies
Make 100 horizontal cuts
250 kills by shurikens
50 kills by shurikens
Complete all challenges
Find all coins in challenges
500 murders in the melee
Complete challenge
Learn all skills in the Shurikenjutsu techniques
150 kusarigama kills
50 kusarigama kills
Learn all skills in the hand-to-hand combat
250 murders in the melee
Kill 100 heavy samurai
Block 10 Shuriken or Arrows
50 murders in the melee
Kill an enemy with skill
Assassinate 10000 enemies
Кusarigama kill
Learn all skills in the Kusarigama combat
Learn all skills in the Shinobigatana combat
Collect 5000 coins
Destroy 200 boxes
Complete all tasks in 1 act
Behead 100 enemies
Make 100 diagonal cuts
Kill Mamoru
Restore the village
Kill Oni
Kill 50 heavy samurai
Kill Fudo
Complete all tasks in 4 act
Assassinate 500 enemies
Kill Tengu
Kill by poison
Kill Tabiakindo
Complete all tasks in 3 act
Kill by shurikens
Kill Jorogumo
Assassinate 250 enemies
Kill 15 heavy samurai
500 kills
Kill first boss
100 kills by explosions
50 kills by explosions
Guess the recipe
Learn all the skills of the blacksmith
Kill Asura
Seppuku
Collect 1000 coins
Murder in melee
Break the Sword
Craft anything
Kill Shutendoji
Kill by explosions
Assassinate 50 enemies
Kill by fire
Collect 500 coins
100 kills
Kill Gashadokuro
Make a purchase
Complete the first mission
Pull the enemy with the hook
Assassination
First kill