Here is the full list of all 55 Onimusha: Warlords achievements.
Complete the game on Ultimate difficulty.
Enhance the gauntlet to maximum.
NEW_ACHIEVEMENUse Magic Jewels to increase Magic Power to maximum._DESC_2_7
Absorb souls from carp.
Find the beetle on the tree trunk.
Complete all stages of Oni Spirits.
Spot the flock of wild geese at dusk.
Complete the game and get an S Rank.
Unlock Kaede's alternate outfit.
Collect all Fluorite.
Obtain the Bishamon Sword.
Complete the second half of the Dark Realm.
Complete the first half of the Dark Realm.
Complete the game on Normal without using herbs or medicine.
Use Power Jewels to increase Vitality to maximum.
Complete the game in less than 3 hours.
Complete the game on Normal without enhancing swords or using Jewels.
Strike Marcellus's final form with a Deflect Critical attack.
Collect all files.
Solve all decoder boxes.
Defeat a demon by knocking it down the waterfall.
Obtain all long-range weapons.
Kill a demon with a battering ram.
Unlock Samanosuke's alternate outfit.
Defeat Fortinbras.
Collect all maps.
Defeat Marcellus's final form.
Open the gate to the Demon World.
Enhance all swords to maximum.
Defeat Hecuba.
Solve all number puzzles.
Strike a demon with Kaede's Special Attack.
Obtain all armor for Samanosuke.
Use the Decorated Sword to enter the East Area.
Enhance all orbs to maximum.
Defeat Barabazuu.
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.
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.
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.