I'm not entirely sure how this works I just know it happens

While experimenting with some ability codes I discovered that
They can be used to change Amarant Eiko and Quina into Blank Marcus and Cinna
They will keep their abilities but will look different in battle only
Their weapons will be changed!

The ability codes I was working with are

No magic stones required to equip abilities
D01EFFEA A222
801EFFEA 2400

And
Infinite magic stones
50000990 0000
3008B2A3 0063

And
All abilities
50000990 0000
3008B296 00FF

I might have had others equiped but I don't remember
Blank and marcus use swords up to the Defender
And cinna ONLY uses his hammer so I suggest you do not change his
Weapon from quina's fork unless you have the codes to equip different weapons
Which can be found on this site from someone else

I also have a code that changes Garnet into Beatrix in battle
But it is a very complicated code which I plan to figure out soon
But if you feel like tinkering with it a bit here it is

Save the Queen
E01F476 00FF
301F476 0008

If I remember right it's something like turn the codes OFF load the file
Turn them ON save turn them OFF get in your airship turn them ON
Switch party members you will LOSE Garnet and Beatrix will be there

SHE WILL NOT HAVE Garnet's SUMMONS THEY WILL BE REPLACED WITH Saikon
Which are beatrix's sword-skills

Thunderslash (Thunder elemental damage)
Stock break (physical damage to all foes)
Climhazzard (non-elemental damage to all foes)
Shock (heavy non-elemental damage to all foes)

Beatrix can ONLY use Save the Queen sword which is 26 atk +2 all stats +5 spirit

A WARNING FOR THOSE WHO USE THE PLAYER CHANGE CODES: DO NOT USE THESE CODES
IF YOU LIKE TO USE TRANCE FOR THESE CODES WILL DISABLE THE TRANCE GAUGE PERMENANTLY!!

ALSO IF YOU USE THE CODES FOR BLANK MARCUS AND CINNA YOU WILL NO LONGER BE ABLE
TO EQUIP OR UN-EQUIP YOUR ABILITIES! WHAT YOU EQUIP STAYS EQUIPED

The inf magic stones works fine without the others though so feel free to use it
I do

Here is some other codes for ya

98 frogs (1 more frog will max quina's frog drop dmg = 9999 every time)
80087B80 0062

This code will max Zidanes Thievery dmg = 9999 dmg every time
800B87BA 1000

And I might as well fork this one over as well

One jump gives 1024 jumps (Disc one only)
D0073930 FCEF
30077E8C 0004

Rods
80069420 FFFF
80069432 FFFF
80069444 FFFF
80069456 FFFF
80069468 FFFF
8006947A FFFF
8006948C FFFF

Rackets
800693B4 FFFF
800693C6 FFFF
800693D8 FFFF
800693EA FFFF
800693FC FFFF
8006940E FFFF

Staffs
8006950A FFFF
8006951C FFFF
8006952E FFFF
80069540 FFFF
80069552 FFFF
80069564 FFFF
80069576 FFFF
80069588 FFFF
8006959A FFFF

Spears
8006924C FFFF
8006925E FFFF
80069270 FFFF
80069282 FFFF
80069294 FFFF
800692A6 FFFF
800692B8 FFFF
800692CA FFFF
800692DC FFFF
800692EE FFFF

Forks
800695AC FFFF
800695BE FFFF
800695D0 FFFF
800695E2 FFFF
800695F4 FFFF
80069606 FFFF

Daggers
80069030 FFFF
80069042 FFFF
80069054 FFFF
80069066 FFFF
80069078 FFFF
8006908A FFFF

Thief Swords
8006909C FFFF
800690AE FFFF
800690C0 FFFF
800690D2 FFFF
800690E4 FFFF
800690F6 FFFF
80069108 FFFF
8006911A FFFF
8006912C FFFF

Swords (Steiners)
8006913E FFFF
80069150 FFFF
80069162 FFFF
80069174 FFFF
80069186 FFFF
80069198 FFFF
800691AA FFFF
800691BC FFFF
800691CE FFFF
800691E0 FFFF
800691F2 FFFF
80069204 FFFF
80069216 FFFF
80069228 FFFF
8006923A FFFF

--HAVE ALL ITEMS--
5000ff02 0001
8008b7b2 05f5

--MAX GIL--
8008b7b0 e0ff
8008b7b2 05F5

--ALL CHARACTERS ABILITIES--
50000990 0000
3008b29B 00ff

Please enter in the form of: code - effect

quinna has all blue magic
dooeeboa1440
800eeboa2400

max choco points
8007af60ffff

Zidane Codes
Unlock All Abilities: 3008B296 00FF
Level 99: 3008B297 0063
Max HP : 8008B2A4 270F
Max MP : 8008B2A6 03E7

Princess Garnet Codes
Unlock All Abilities: 3008B3B6 00FF
Max HP: 8008B3C4 270F
Max MP: 8008B3C6 03E7
Max Speed: 3008B3D0 0063
Max Strength: 3008B3D1 0063

I have loads and loads of codes so here's a few for a couple of the main characters.

ZIDANE
37E81BABC234-ALL ABILITIES UNLOCKED
B7A878383535-ALL ABILITIES ACTIVE
3727DC0A3244-HAVE BEST WEAPON EQUIPPED
87B734BE5944-INFINITE HP
870536B8D51C-INFINITE MP

VIVI
37970C3BC234-ALL ABILITIES UNLOCKED
B7A878383535-ALL ABILITIES ACTIVE
87B42748D51C-INFINITE MP

THAT'S ALL I'LL GIVE.

FOR NOW ANYWAY...

Wuz up people, this is Goku/Raziel, now known as li4evr.

I don't know if you know, but the gameshark codes some people put in will work, except that certain ones might screw up your game.

There are a lot of sources where you can get cheats. mine are playonline.com and gameshark.com. the codes I have will help alot for those that are stuck in/on a particular area.

Have All Items:5000FF02 0001
8008B7C4 6301

Max Gil:8008B7B0 E0FF
8008B7B2 05F5

NO DRAWS (CARD GAME):8008324C 0000

HOLD R2 TO ALWAYS GET "PRESS X":
D0073B9A FDFF
80077E8E 0104
DOO73B9A FDFF
8007BA0A 0074

ZIDANE ALL ABILITIES:50001802 0000
8008B2EC FFFF

VIVI ALL ABILITIES:50001002 0000
8008B38C FFFF

DAGGER/GARNET ALL ABILITIES:
50001002 0000
8005B41C FFFF

STEINER ALL ABILITIES:50001602 0000
8008B4A0 FFFF

FREYA ALL ABILITIES:50001002 0000
8008b52c ffff

QUINA ALL ABILITIES:50001002 0000
8008B5CC FFFF

EIKO ALL ABILITIES:50001002 0000
8008B65C FFFF

AMARANT ALL ABILITIES:50001002 0000
8008B6DC FFFF

VIVI INF. MP:87B42748 D51C

Now all you need is a gameshark and spend 10 minutes or so putting in the code to it.

These will work I got them from Gameshark.com. If you want to, you can check it out yourself.

I'll give other info. later about the game, but just so you know, one reason you have difficulty is your trying to steal their items that they have.