To unlock a New Game + in which you carry over weapons, experience and armor, the difficulty is harder, and souls earned increases, beat the game. Each time you beat the game it will become more difficult.
Halloween mode:
To unlock Halloween mode in which the enemies become more difficult and give better rewards, change the PS3's system date to October 31st.
Farming Souls:
A good place to farm is in The Shrine of Storms. Equip your Ring of Avarice the Viscous Compound Long Bow +5, arrows, and the 4-2 Archstone. Go down the hall passing Graverobber
Blige and stand at the edge of the floor. Fire down at the reaper. Then, fall off of the cliff to respawn and get your bloodstain. Repeat as desired.
Keep Souls after dying:
To keep your souls after you die, quickly hit the PS button and quit the game before it auto-saves. You can re-load the game with all your souls.
Thief Ring and Cling Ring locations:
Cling Ring
In the first level after you get to the top of the castle, you'll fight a blue demon knight that's right in front of a fog gate. Beat him then go past him, not into the fog gate, and go down the stairs, when you reach the bottom there will be a lever to open the gate and you will find the Cling Ring which lets you keep more health when in soul form.
Thief Ring
After the first blue demon knight, go through the Fog gate, and you'll come to some stairs and you'll see over the ledge will be a gold knight. Roll down the side of the stairs to the ledge to get to where he is. The Thief ring is located behind him in the corner.
Item and Soul Duplication:
To duplicate items and souls, you will need two players, Lengedary Heros Souls, and an item you drop from weapons to other souls. First, summon a black or blue phantom. Have the phantom drop the items you want to duplicate. Then have him quit the game by pressing the PS button. Summon him back and have him drop more items and have him quit again. He will keep the items which he dropped and you can collect the duplicated items. You can do this with Legendary Hero's and Soldiers Souls.
Boletarian Palace mausoleum key:
To get the key to the mausoleum in Boletarian Palace, you normally have to save Ostrava's life three times. Instead, you can kill him the first time that you meet him and take the key from him.
Hidden items in Boletarian Palace:
After you kill the Red Dragon go back to the Boletarian Palace where the two dragons were sleeping to get the Ring of Fire Resistance, Renounced Hero Soul, and the Ring of Strength.
Blinding the Maneaters:
To blind Maneaters, equip the Dark Silver Shield. The Maneaters snake tails will sometimes give them a yellow colored power. Stand directly in front of them and guard when the snake tail rises above them and the yellow flash will temporarily blind the Maneater making him vulnerable to a few heavy hits.
Defeating the Red Dragon:
To defeat the Red Dragon on the bridge going to the Tower Knight, get a crossbow and 100 bolts. Go to the top of the first tower and kill the two archers. Go to the archer window on the far right and lock on to the dragon every time he swings down to burn the bridge. It will take a while, but after killing him you will receive 8,000 souls and his lead soul.
Trophies:
Bronze trophies
Battened Knight - Overthower of the demon "battened knight".
Hill Accumulator - Overthower of the demon "hill accumulator".
Idol of the Idiots - Overthower of the demon "idol of the idiots".
Impure Giant - Overthower of the demon "impure giant".
King's Flying Dragon - Overthower of the demon "king's flying dragon".
Knight of the Tower - Overthower of the demon "knight of the tower".
Man Eater - Overthower of the demon "man eater".
Old Brave Warrior - Overthower of the demon "old brave warrior".
Old King - Conqueror of the old king doran.
Phalanx - Overthower of the demon "phalanx".
Takaashi Armored Spider - Overthower of the demon "takaashi armored spider".
The Judge - Overthower of the demon "judge".
The One Hidden in the Flames - Overthower of the demon "the one hidden in the flames".
The One to Master Blessing - Obtained the best dim light stone weapon.
The One to Master Blood - Obtained the best sucking stone weapon.
The One to Master Fire - Obtained the best dragon stone weapon.
The One to Master Hardness - Obtained the best hard stone weapon.
The One to Master Life - Obtained the best medulla stone weapon.
The One to Master Moon Shadow - Obtained the best moon shadow stone weapon.
The One to Master Poison - Obtained the best mercury stone weapon.
The One to Master Shade - Obtained the best thin cloud stone shield.
The One to Master Sharpness - Obtained the best sharp stone weapon.
The One to Master Shock - Obtained the best nibi stone weapon.
The One to Master the Cutting Attack - Obtained the best cutting stone weapon.
The One to Master the Moonlight - Obtained the best moonlight stone weapon.
The One to Master the Viscous Bow - Obtained the best bow by the steel spider`s thread.
The One to Understand the Difference - Obtained the best minagi stone weapon.
Silver trophies
God of the Dragon - Overthower of the demon "god of the dragon".
Incarnation of the King - Overthower of the demon "incarnation of the king".
Storm King - Overthower of the demon "storm king".
The Maiden Asutoraea - Overthower of the demon "asutoraea".
Yellow-Robe Elder - Overthower of the demon "yellow-robe elder".
Gold trophies
Hidden One - The one to obtain all rings.
Saint - The one to acquire all the miracles.
Soldier - The one to obtain all valuable equipment.
The One to connect the world - Guiding the beast of spread back to slumber once more, you have stopped and connected the World.
Wise - The one to acquire all the magics.
Platinum trophy
Strong Soul - The one to obtain all trophies
