To activate the following cheats, go to "Main Menu" > "Multiplayer" > "Friend Card Settings" > "Friend Card Edit". Clear all the text, and enter the corresponding codes using the second English character set by pressing Select three times. Exit the lobby:

Ghosts
GHOST - CHEAT CODE
Auron - 1298228499
Ahriman - 1191170358
Bash - 7140337848
Behemoth -
Cait Sith - 5237017057
Death Machine - 651738986
Fusuya - 29432971
Gilgamash - 33906088
Laguna - 25315075
Matoya - 3939258263
Ming-Wu - 2015944102
Ninja - 2748173856
Omega - 812417748
Ragna -
Red Wing Ace - 228451809
Seifer - 6764925796
Shantotto - 4797837576
Siegfried - 20151231
Steiner - 473897101
Ultros (Oltoross) - 2193355016
Vivi - 3784227940
Wakka - 49326576
Yuffie - 8672142937

Player icons
ICON - CHEAT CODE
Chocobo - 582052436
Final Fantasy XIII - 5632121231
Final Fantasy XIII - 589786789
Final Fantasy Agito XIII - 3881459361
Final Fantasy Agito XIII - 4460725253
Final Fantasy Versus XIII - 4273120192
Final Fantasy Versus XIII - 361855216
Moogle - 134103103

Recipes
RECIPE - CHEAT CODE
Aquarius - 3927540667
Aries - 6798067239
Cancer - 1125877315
Capricorn - 870322642
Gemini - 1137250106
Leo - 2367933714
Libra - 901104871
Pisces - 531062973
Sagittarius - 884911049
Scorpio - 6535897932
Taurus - 897651643
Virgo - 93702898