My love for FF6 is past the obsessed range, so with that, I'll share my knowledge with those who love this game, or will be starting with it.
First, and foremost, the Gau/Relm glitch only works on the SNES release, and only version 1.0. 1.1 and later versions and remakes have this glitch patched (as far as I know).
The Gau/Relm glitch is one of the best glitches in all video games. Actually, there's a few different ways to execute this trick, and you can do it as soon as you get Relm in your party. The reason the glitch happens is because it points to a bad memory location and causes "undesirable" effects. In this case, it performs the best effects - unlimited items, for free.
Simply sketch a monster, and the battle will completely screw up. Wait for the game to correct itself (or if you're able to, finish the battle). Once you're back on the overworld, go into your inventory and you will see a world of items. Some will have the amounts of 1 through 99, others will have 0. 0?! Dafuq?! Simply go to sell the item, and you actually have 256 of said item, and you will have several items of the same name.
Here's a video I did a few months back: https://www.youtube.com/watch?v=NfvD99xSTAQ
Heed the warning: any items you want to keep, EQUIP THEM ON CHARACTERS IN THE AIRSHIP. You have the potential to "lose" the items if they're in a location where new items will be placed. Each battle formation produces different results. One, in particular, will give you 99 Illumina Swords. People claim this also has the ability to erase all saved games on the cart. I've never once experienced this.
Leveling Guide:
I'm going to only use 2 characters for this guide, as once you learn this, you can apply it to anyone.
Assumptions: You're in the World of Ruin and you've collected all your party members back, and have all the espers (except Crusader, no need for that for this guide). Levels should be between 23 and 28 (use the Vanish + X-Zone trick, and on bosses use Vanish + Doom. Doomgaze will not drop the esper with Vanish+X-Zone, so use Vanish+Doom. Use X-Zone on Wrexsoul because you still get Alexander anyway).
Average level should be 28.
Before the World of Ruin, as soon as you get the esper Stray, equip Terra with it, and keep it on until you get Zoneseek (you will get Stray way before level 28).
Equip Terra with Zoneseek (or Tritoch) (At level up, MagPwr+2). Do this until her MagPwr is 128 (I think it stops there, or stops shortly after, maybe 136? Just save before Leveling up so that way you don't over level using this esper). Equip her with the Illumina Sword, Force Shield, Minerva (can be Force Armor). After Zoneseek, equip her with Fenrir for X levels and switch over to Terrato. Fenrir gives 30% MP on level up (30% more of what your level increase is), and Terrato is 30% more HP. You could also use Bahamut and Crusader (50% bonus to HP and MP, respectively). The X levels can be whatever you want. Chances are, you won't get both maxed out since you're using Zoneseek to boost your MagPwr. I usually max out HP, and toss on the Gem Box and Economizer. I need to replay this because I forget which one does which, but either the Force Armor or Minerva will absorb some of those awesome spells (Merton, Whirl Wind, Quake, etc), and the other reduces it to 0. Max out her MagPwr, and cure 1 will heal 7000+ hp. At this point, the Economizer is nearly useless since you can deal 9,999 damage using a level 2 spell. With her mblock high from the gear, most spells will be evaded.
Next up, Shadow:
As soon as you get the Esper Odin, equip Shadow with until leveling up doesn't increase his speed. Once maxed out, he will be able to attack twice before anyone else. This also makes him practically immune to physical attacks.
After anyone levels up, especially if you're fighting in Dino forest, SAVE. If you die, and continue on, all level up bonuses from espers are GONE.
Alternatives to the Relm/Gau glitch to get more economizers and gem boxes:
Dino forrest, Brach's will drop Gem Boxes (rare drop), and you can steal Ribbons (I believe). Tyro's will drop Economizers.
When given the choice for Ragnarok Sword or Esper, choose Sword. Get the cursed shield and a ribbon, equip the ribbon and shield to someone and fight 255 battles to get the Paladin Shield (this might be a better choice instead of the Force shield, but if I remember correctly, it's not). Paladin Shield will allow people to learn Ultima (as will the Ragnarok Sword). Go to the Veldt and have Terra learn Ultima, go wager the Ragnarok Sword at the Colosseum to get the Illumina Sword.
For fast leveling, get the Experience Egg in Darryls Tomb, and if you have a tintina bar, I believe if you wager that at the Colosseum, you get another Exp. Egg. Equip both when you can take on Tyros and Brachs solo, and you'll level to 99 in about 2 hours (as long as you're solo in the party, or everyone is dead).
Enjoy pure and total domination
First, and foremost, the Gau/Relm glitch only works on the SNES release, and only version 1.0. 1.1 and later versions and remakes have this glitch patched (as far as I know).
The Gau/Relm glitch is one of the best glitches in all video games. Actually, there's a few different ways to execute this trick, and you can do it as soon as you get Relm in your party. The reason the glitch happens is because it points to a bad memory location and causes "undesirable" effects. In this case, it performs the best effects - unlimited items, for free.
Simply sketch a monster, and the battle will completely screw up. Wait for the game to correct itself (or if you're able to, finish the battle). Once you're back on the overworld, go into your inventory and you will see a world of items. Some will have the amounts of 1 through 99, others will have 0. 0?! Dafuq?! Simply go to sell the item, and you actually have 256 of said item, and you will have several items of the same name.
Here's a video I did a few months back: https://www.youtube.com/watch?v=NfvD99xSTAQ
Heed the warning: any items you want to keep, EQUIP THEM ON CHARACTERS IN THE AIRSHIP. You have the potential to "lose" the items if they're in a location where new items will be placed. Each battle formation produces different results. One, in particular, will give you 99 Illumina Swords. People claim this also has the ability to erase all saved games on the cart. I've never once experienced this.
Leveling Guide:
I'm going to only use 2 characters for this guide, as once you learn this, you can apply it to anyone.
Assumptions: You're in the World of Ruin and you've collected all your party members back, and have all the espers (except Crusader, no need for that for this guide). Levels should be between 23 and 28 (use the Vanish + X-Zone trick, and on bosses use Vanish + Doom. Doomgaze will not drop the esper with Vanish+X-Zone, so use Vanish+Doom. Use X-Zone on Wrexsoul because you still get Alexander anyway).
Average level should be 28.
Before the World of Ruin, as soon as you get the esper Stray, equip Terra with it, and keep it on until you get Zoneseek (you will get Stray way before level 28).
Equip Terra with Zoneseek (or Tritoch) (At level up, MagPwr+2). Do this until her MagPwr is 128 (I think it stops there, or stops shortly after, maybe 136? Just save before Leveling up so that way you don't over level using this esper). Equip her with the Illumina Sword, Force Shield, Minerva (can be Force Armor). After Zoneseek, equip her with Fenrir for X levels and switch over to Terrato. Fenrir gives 30% MP on level up (30% more of what your level increase is), and Terrato is 30% more HP. You could also use Bahamut and Crusader (50% bonus to HP and MP, respectively). The X levels can be whatever you want. Chances are, you won't get both maxed out since you're using Zoneseek to boost your MagPwr. I usually max out HP, and toss on the Gem Box and Economizer. I need to replay this because I forget which one does which, but either the Force Armor or Minerva will absorb some of those awesome spells (Merton, Whirl Wind, Quake, etc), and the other reduces it to 0. Max out her MagPwr, and cure 1 will heal 7000+ hp. At this point, the Economizer is nearly useless since you can deal 9,999 damage using a level 2 spell. With her mblock high from the gear, most spells will be evaded.
Next up, Shadow:
As soon as you get the Esper Odin, equip Shadow with until leveling up doesn't increase his speed. Once maxed out, he will be able to attack twice before anyone else. This also makes him practically immune to physical attacks.
After anyone levels up, especially if you're fighting in Dino forest, SAVE. If you die, and continue on, all level up bonuses from espers are GONE.
Alternatives to the Relm/Gau glitch to get more economizers and gem boxes:
Dino forrest, Brach's will drop Gem Boxes (rare drop), and you can steal Ribbons (I believe). Tyro's will drop Economizers.
When given the choice for Ragnarok Sword or Esper, choose Sword. Get the cursed shield and a ribbon, equip the ribbon and shield to someone and fight 255 battles to get the Paladin Shield (this might be a better choice instead of the Force shield, but if I remember correctly, it's not). Paladin Shield will allow people to learn Ultima (as will the Ragnarok Sword). Go to the Veldt and have Terra learn Ultima, go wager the Ragnarok Sword at the Colosseum to get the Illumina Sword.
For fast leveling, get the Experience Egg in Darryls Tomb, and if you have a tintina bar, I believe if you wager that at the Colosseum, you get another Exp. Egg. Equip both when you can take on Tyros and Brachs solo, and you'll level to 99 in about 2 hours (as long as you're solo in the party, or everyone is dead).
Enjoy pure and total domination
