In the 2nd half of the game, find Cyan and sleep in Doma Castle, in the dream when your in the train, youll find the Genji Glove relic, which lets you hold 2 weapons for 2 attacks. Then travel using Figaro Castle until you get to Ancient Castle, go to the 2 doors to the left of the main entrance and open the chest, defeat Samurai Soul and recieve the Master's Scroll relic, allowing 4 attacks. Give the Genji Glove and Masters Scroll to Cyan, Sabin, or another hard-hitting character, and they will be able to perform 8 attacks, 4 for each weapon!
Awesome relic
In the world of ruin (near the east side)there should be a tower surrounded by mountains. Go into the tower via airship and put the best people at magic in your party (because you're only allowed to use magic in the tower) keep going up the stairs of the tower until you get to the top (after about 1 hour). Go into the room and get the gem box (X-magic) out of the chest and before leaving equip it to your strongest magic warrior (mine was terra). It is also a great idea to give your character with the most hp a hp raising relic/equip(I had a red cap that raised hp by 20%). Exit the room and wait for the scene to finish, you will now battle a real tough boss as he keeps using an ability that changes his element. Cast shell on the character with the most health. Now, randomly cast different Fire 3/Ice 3/Bolt 3 spells. Once his hp reaches 0 he will counter-attack with ULTIMA, your character with the most hp and shell should still be alive and you win the battle! Gem box is a great relic as you can use 2 spells in one turn. Works well with a gold hairpin relic as it halfs mp consumes so you can use 2 spells for the price of 1!!
Note: you do not have to go all the way back down the tower, it will automatically do that when you defeat the boss.
Bestiary
Save the game at any option to unlock the 'Bestiary' option at the 'Extra' menu.
Dragon's Den
Defeat the 8 Dragons in the World of Ruin. This dungeon is located at North-West of the world map.
Espers Locations
There are two espers in the auction house Zona Seeker is 10,000 gil. and Golem is 20,000 gil.
This one can be found on both worlds.
Go to Tzen and go to the Relics shop DON'T GO INSIDE walk along the side of the building next to the trees and you will see a man walking in the woods talk to him he will give you Seraph for 3,000 Gil. (Get this esper before you go to the Floating Continent!)
On the secend world go to the beach where you had to catch fish for Cid there will be a esper there.
(If it is not there go and find more party members and come back).
On the secend world fly around the triangle island and you will run in to a esper.(He's hard! make sure you are worked up will!)After you defeat him press the start buttion and walk to the front of your ship there will be your esper!
If anyone knows where more are at please lsit them.
Get Diabolos Without Fighting the Kaiser Dragon
Normally, you need to defeat the hardest boss in the game, the "Kaiser Dragon" to be able to win the Diabolos magicite. However, You can skip the tough battle altogether and still recieve Diabolos.
Step 1:
Get to the Kaiser Dragon and stand directly in front of him without tapping A to initiate the fight.
Step 2:
Go to your menu then select "Equip", and go in to any of your characters' equip screen.
Step 3:
After checking your equipment in front of the Kaiser Dragon, exit your menu and hold forward. When you return to the game you will walk right through the Kaiser Dragon and be able to proceed without fighting him!
Now walk to the shiny light and collect your new Diabolos magicite and take the warp back outside of the dungeon. Note: This will not unlock the Soul Shrine. You must defeat Kaiser Dragon normally to unlock it.
Get Mythril Pike And Mythril Shield Early
When in the mines during the save Terra scenario with Locke and the Moogles, go to Mog's party and unequip Mog of his Mythril Pike and Mythril Shield.
Give Terra More Experience
In the beginning when you first enter Narshe with the two imperial soldiers, use Terra's (??????) fire magic to kill off the two guards. All of the experience will be directed to Terra, a main character.
Intangir
The Intangir enemy can no longer be affected by the Vanish-Doom trick.
Music Player
Successfully complete the game to unlock the 'Music Player' option at the 'Extra' menu.
Psycho Cyan Advance
The famous glitch from the SNES version, revisited. This time, there's a new method to trigger it.
Step 1: In battle, kill Cyan.
Step 2: Revive Cyan.
Step 3: Have Cyan use his Level 2 Bushido, "Sky," previously known as "Retort."
Step 4: Cast "Imp" on Cyan.
Step 5: Watch in awe as Cyan loses his mind and proceeds to attack continuously, uninterrupted, until every enemy is dead.
This glitch is the result of two smaller bugs involving "Imp" Status and being revived in combat; one that makes Cyan counter with physical attacks, rather than the "Sky" move, and another that makes Cyan counter any move performed by any character, not just a physical attack from the enemy to Cyan. As you can see, activating this glitch is done differently from the original SNES version of the game, but it results in the same thing: Cyan countering his own counterattack over and over again, until the battle is won.
Save Cid
When you're supposed to catch some fish for Cid, be sure to catch the fast ones that moves around in the water and give those to Cid so he can live. If you catch the slow ones and feed them to Cid, he'll die because the slow ones are the sick fish and the fast ones are the healthy ones.
Save/Use Tents Virtually Anywhere
This neat little trick from FF3US for the SNES still works, and with the addition of the new post-game hidden dungeon, it's even more useful!
Have one of your teams in a multi-team dungeon move onto a Save Point. Next, switch over to one of your other teams. As long as you remain stationary with this second team, you can Save your game, or even better, use a Sleeping Bag or Tent for quick and easy healing!
Should your party move out of place or if you want to save/use a tent again later on, simply switch back to the team on the save point, switch back to the party you wish to save with/heal, remain on one space, then do as you will.
Soul Shrine
Clear the Dragon's Den and beat the game. This secret dungeon is located on one of the small islands at North of Mobliz.