Complete the Demon Realm in Mont-Saint-Michel with Jacque to unlock Ako's Purple Vest.

This Vest decreases the amount of Oni power used (when you atack with the swords) by Half.

Hope I helped.

Raizan=Thunder element no charge attacks can be obtained from thunder seal from dr .Attack power rating:8/9, Special thunder shock

Enryuu=Fire element no charge attacks can be obtained from fire seal from dr
Attack Power Rating:8/9, Special fire blast

Shipuu=Wind element no charge attacks can be obtained from wind seal from dr
Attack power 8, special tornado

Tenso=light element charge attacks obtained in Arc of triumphe: Attack power 7/8

Special ten slashs
Kuga = wind element charge attacks obtained in Notre Dame : Attack Power 7-9
Special wind wave can chop in half

Chigo=Earth Element charge attacks obtained in under sea temple Attack power 8/9 special eruptions

Bishamon Sword=Dark element charge attacks obtained in dark realm attack power 9/10 special semi invincble slash

Onimusha sword=Oni element charge attacks obtained in final battle Attack power 10+

New Ending:

Find all Kodama which you will need and increase all 7 Haori of Ako to maximum.

Get Hard Difficulty:

Finish the game using normal difficulty.

Get Easy Difficulty:

Lose the game 2 times using the normal difficulty setting.

Get Issen Difficulty:

Finish the game using the hard difficulty setting.

Get Oni Hard Difficulty:

Finish the game using the Issen difficulty setting.

Unlock Panda Costume:

Finish secret training mode OR play the game with a memory card with a save game from Onimusha Blade Warriors.

Get Michelle's New Outfit:

Finish the game using normal difficulty.

Get Michelle's New Outfit:

Finish the game and get a Onimusha rank. OR play the game with a memory card with a save game from Onimusha Blade Warriors.

Get Jacuge's New Outfit:

Finish the game using normal difficulty.

Unlock Puzzle Mini Game:

Finish all the puzzles in the game.

Unlock Ako's Black Haori:

Finish Issen/Oni training.

Unlock Bishamon Sword:

Finish the game and get a Onimusha rank OR get the sword when Sam goes to the Past in the Phanton Realm in Honnouji.

Get All 3 Original Onimusha Swords:

Finish the game and have 3 items from the Phanton Realms and start a new game.

Unlock Ultimate Mode:

Finish the Oni Shooting Mini Game.

This will start the game with unlimited arrows, bullets, Oni Power, 10 Talismans, 30 medicines, Jacque with best Oni Musou and Sam with Bishamon Sword.