Here is the full list of all 55 Onimusha: Warlords achievements.
Unlock Samanosuke's alternate outfit.
Defeat Fortinbras.
Collect all maps.
Obtain the Bishamon Sword.
Defeat Marcellus's final form.
Open the gate to the Demon World.
Enhance the gauntlet to maximum.
Complete the second half of the Dark Realm.
Collect all Fluorite.
Complete the first half of the Dark Realm.
Defeat Hecuba.
Solve all number puzzles.
Enhance all swords to maximum.
Use Power Jewels to increase Vitality to maximum.
Solve all decoder boxes.
Obtain all armor for Samanosuke.
Use the Decorated Sword to enter the East Area.
Obtain all long-range weapons.
Defeat Barabazuu.
Kill a demon with a battering ram.
Obtain the Vision Staff.
Defeat Stylado.
Obtain the Sacred Knife.
Cut down bamboo in the bamboo forest.
Speak to the first and second old moth man.
Obtain the Rosary of Communication.
Enhance all orbs to maximum.
Unseal the path to the Keep Underground.
Obtain the Arashi.
Defeat Marcellus.
Solve the crest puzzle.
Win a power struggle with a demon.
Enter the abandoned keep.
Use a Special Attack to kill a demon.
Obtain the Kouen.
Defeat Osric.
Enhance equipment at Magic Mirror.
Save a soldier under attack by demons.
Obtain the Shiden.
Use the gauntlet to absorb demon souls.
Complete the game on Normal without enhancing swords or using Jewels.
Complete the game on Ultimate difficulty.
Complete the game on Normal without using herbs or medicine.
Complete the game in less than 3 hours.
Complete the game and get an S Rank.
Complete all stages of Oni Spirits.
Collect all files.
Unlock Kaede's alternate outfit.
NEW_ACHIEVEMENUse Magic Jewels to increase Magic Power to maximum._DESC_2_7
Strike a demon with Kaede's Special Attack.
Strike Marcellus's final form with a Deflect Critical attack.
Defeat a demon by knocking it down the waterfall.
Spot the flock of wild geese at dusk.
Find the beetle on the tree trunk.
Absorb souls from carp.