Here is the full list of all 55 Onimusha: Warlords achievements.
Complete the game and get an S Rank.
Unlock Kaede's alternate outfit.
Complete the game on Ultimate difficulty.
Complete all stages of Oni Spirits.
Complete the game in less than 3 hours.
Complete the game on Normal without enhancing swords or using Jewels.
Complete the game on Normal without using herbs or medicine.
Strike a demon with Kaede's Special Attack.
Find the beetle on the tree trunk.
Spot the flock of wild geese at dusk.
Strike Marcellus's final form with a Deflect Critical attack.
Collect all Fluorite.
Absorb souls from carp.
NEW_ACHIEVEMENUse Magic Jewels to increase Magic Power to maximum._DESC_2_7
Defeat a demon by knocking it down the waterfall.
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.
Complete the first half of the Dark Realm.
Enhance all swords to maximum.
Defeat Hecuba.
Collect all files.
Solve all number puzzles.
Solve all decoder boxes.
Win a power struggle with a demon.
Obtain all armor for Samanosuke.
Use Power Jewels to increase Vitality to maximum.
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.
Enhance all orbs to maximum.
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.
Unseal the path to the Keep Underground.
Obtain the Arashi.
Defeat Marcellus.
Solve the crest puzzle.
Enter the abandoned keep.
Obtain the Kouen.
Defeat Osric.
Save a soldier under attack by demons.
Use a Special Attack to kill a demon.
Enhance equipment at Magic Mirror.
Obtain the Shiden.
Use the gauntlet to absorb demon souls.