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 in less than 3 hours.
Complete the game on Ultimate difficulty.
Strike Marcellus's final form with a Deflect Critical attack.
Absorb souls from carp.
Find the beetle on the tree trunk.
Spot the flock of wild geese at dusk.
Strike a demon with Kaede's Special Attack.
Complete all stages of Oni Spirits.
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 all swords to maximum.
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.
Collect all files.
NEW_ACHIEVEMENUse Magic Jewels to increase Magic Power to maximum._DESC_2_7
Solve all decoder boxes.
Obtain all armor for Samanosuke.
Defeat a demon by knocking it down the waterfall.
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.
Enhance all orbs to maximum.
Speak to the first and second old moth man.
Obtain the Vision Staff.
Defeat Stylado.
Obtain the Sacred Knife.
Cut down bamboo in the bamboo forest.
Win a power struggle with a demon.
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.
Enhance equipment at Magic Mirror.
Save a soldier under attack by demons.
Obtain the Shiden.
Use a Special Attack to kill a demon.
Use the gauntlet to absorb demon souls.
Complete the game on Normal without enhancing swords or using Jewels.
Complete the game on Normal without using herbs or medicine.