Sun Sword

Sprite
Damage 32
Crit 12%
Hit +30%
V. 10,000 G

Equipped By

Found In Mirage Tower 2F
The Sun Sword is the first Weapon you're likely to find to replace the Ice Sword you've had since Gurgu Volcano—it is powerful and extremely accurate. Not only that, but it's the best Weapon (other than the Masmune) that a RedWiz can use. Your KNIGHT will make excellent use of it until you obtain the Xcalber, or a NINJA can use it until you find a Katana.
Compare Sun Sword to other Weapons
Treasures: Containing Sun Sword – 1 shown
Map
The specifics of where this treasure can be found
Notes
Mirage Tower 2F In the third chest from the top on the right side of the main room
Giant Sword Coral Sword

Related

The Mirage Tower

The ORB of Wind
Page 2
Use the CHIME to enter the Mirage Tower, collecting Treasure and learning that you need the CUBE to proceed further.

Sunblade

Sword effective against the undead.
Damage 32
Crit 12%
Hit +30%
Effective Against Undead
Value 10,000 gil (10,000 gil on Easy)
Found In Tower of Mirage 2F

Equipped By

The Sunblade is the first Weapon you're likely to find to replace the Ice Brand you've had since Mt. Gulg. it is powerful, extremely accurate, and is extra effective against Undead. Not only that, but it's the best Weapon (other than the Masamune) that a Red Wizard can use. Your Knight will make excellent use of it until you obtain the Excalibur, or a Ninja can use it until you find a Sasuke.

Sun Blade

Sprite
Attack +4
Type Sword
No. 15 Game FFI
Dropped By Ahriman
Be friendly to the environment as you fell foes with this solar-powered sword.

Sun Blade

Sprite
Attack
83
Accuracy
+65%
Type (Icon)Sword
Evasion Bonus +1% × ((Icon)Sword skill + 1)
Magic Penalty 50%
Effective Against Undead
Value 12,500 gil
Found In Castle Palamecia 6F
Dropped By Black Knight
The Sun Blade is a nice upgrade over the Defender, though its attack is only 5 higher so if you need the extra evasion, you may not want to upgrade. It is especially powerful against Undead, though few Undead have enough HP and defense for this to make much difference, aside from the nasty Imperial Shadow creatures you occasionally run into.