Kingdom Hearts 358/2 Days Cheats

Dual-wielding Roxas character in Mission Mode
Buy Zero Gear from the Moogle Shop after completing the game, equip it with Roxas, and add three Ability Units. If you are playing Mission Mode, this will let you play as dual-wielding Roxas. (In Story Mode, Zero Gear will gain the three abilities from the ability units, but it will revert to its original form, and you will not be able to dual wield.)

Freebie Items from Sythesis Moogle
By getting Challange Sigils from Holo-Mission challenges, you can unlock free items that will be given to you by the Sythesis Moogle.

Casual Gear (2): Obtain 15 Sigils
Cure x 3: Obtain 25 Sigils
Fira x 2: Obtain 45 Sigils
Fire x 3: Obtain 20 Sigils
Haste: Obtain 10 Sigils
Phantom Gear+ (4): Obtain 70 Sigils
Slot Releaser: Obtain 5 Sigils
Slot Releaser: Obtain 50 Sigils
Slot Releaser: Obtain 80 Sigils
Slot Releaser: Obtain 30 Sigils
Thundara x 2: Obtain 60 Sigils
Thunder x 3: Obtain 35 Sigils
Wild Gear+ (3): Obtain 40 Sigils

Freebies for Crowns
To unlock crowns do missions on mission mode or multiplayer mode and beat the mission to get crowns. Then go to the shop and choose freebies to redeem prizes.

Adamanite X 2 (material): 180 crowns
Aero X 3 (magic): 25 crowns
Aeroga (magic): 130 crowns
Aerora X 3 (magic): 80 crowns
Blizzara X 2 (magic): 40 crowns
Blizzard X 3 (magic): 15 crowns
Crimson Blood (ring): 160 crowns
Cura X 2 (magic): 35 crowns
Elixir X 10: 70 crowns
Ether X 10: 8 crowns
Guard Unit (L): 240 crowns
Hi-Ether X 10: 55 crowns
Hi-Potion X 10: 50 crowns
Lift Gear+ (3) (weapon): 10 crowns
Limit recharge X 5: 75 crowns
LV Doubler (6): 260 crowns
LV Quadrupler (3): 220 crowns
Magic unit (L): 190 crowns
Master's Circle (ring): 358 crowns
Mega-Ether X 10: 100 crowns
Mega-potion X 10: 90 crowns
Megalixir X 5: 120 crowns
Mystery Gear (3) (weapon): 60 crowns
Panacea X 10: 30 crowns
Potion X 10: 5 crowns
Power Unit (L): 170 crowns
Premium Orb (material): 140 crowns
Rune Ring (ring): 200 crowns
Sliding Dash LV+ (L): 150 crowns
Slot Realeaser: 65 crowns
Slot Releaser: 20 crowns
Slot releaser: 280 crowns
Slot Releaser: 45 crowns
Slot Releaser: 85 crowns
Slot Releaser: 1 crown
Ultimate Gear (6) (weapon): 110 crowns
Valor Gear+ (2) (weapon): 2 crowns

Unlock Limit Pass
To unlock the Limit Pass, beat every mission in Mission Mode at least once, including the first tutorial mission and the Vacation mission. You will earn Crowns next to every mission you complete, and once you get them all, the Limit Pass will be sold in the Moogle Shop for 10,000 heart points