Demon's Souls Cheats

Takaashi Armored Spider (Bronze): Overthower of the Demon "Takaashi Armored Spider".
The Judge (Bronze): Overthower of the Demon "Judge".
The Maiden Asutoraea (Silver): Overthower of the Demon "Asutoraea".
The One Hidden in the Flames (Bronze): Overthower of the Demon "The One Hidden in the Flames".
The One to connect the world (Gold): Guiding the beast of spread back to slumber once more, you have stopped and connected the World.
The One to Master Blessing (Bronze): Obtained the best dim light stone weapon.
The One to Master Blood (Bronze): Obtained the best sucking stone weapon.
The One to Master Fire (Bronze): Obtained the best dragon stone weapon.
The One to Master Hardness (Bronze): Obtained the best hard stone weapon.
The One to Master Life (Bronze): Obtained the best medulla stone weapon.
The One to Master Moon Shadow (Bronze): Obtained the best moon shadow stone weapon.
The One to Master Poison (Bronze): Obtained the best mercury stone weapon.
The One to Master Shade (Bronze): Obtained the best thin cloud stone shield.
The One to Master Sharpness (Bronze): Obtained the best sharp stone weapon.
The One to Master Shock (Bronze): Obtained the best Nibi stone weapon.
The One to Master the Cutting Attack (Bronze): Obtained the best cutting stone weapon.
The One to Master the Moonlight (Bronze): Obtained the best moonlight stone weapon.
The One to Master the Viscous Bow (Bronze): Obtained the best bow by the steel spider`s thread.
The One to Understand the Difference (Bronze): Obtained the best Minagi stone weapon.
Wise (Gold): The One to acquire all the magics.
Yellow-Robe Elder (Silver): Overthower of the Demon "Yellow-Robe Elder".

Keep Souls, Get a Chance to "do-over" if You Die
If you hit the PS button and select "quit game" or, alternatively but not recommended, cut the power to your PS3 immediately as your character dies before the game has a chance to auto-save, when you reload, you will be near where you were originally with all your souls in-tact. Make sure to do it quickly, you run no risk of damaging your save file if you do it this way.