Sasuke

A light ninja blade.
Damage 33
Crit 19%
Hit +35%
Value 30,000 gil (30,000 gil on Easy)
Found In Flying Fortress 3F, Temple of Chaos Past B2

Equipped By

The Sasuke is the best Weapon a Ninja can use, other than the Masamune. It's not a huge upgrade over the Sunblade and Defender, but every little bit helps. This sword is intended to have a very high crit rate like the Vorpal Sword, but due to the same bug that makes the Vorpal Sword pointless, this is not actually the case. Strangely, you can find a second Sasuke in the Temple of Chaos Past. If you happen to have two Ninjas, I guess that would be useful.
Compare Sasuke to other Weapons
Treasures: Containing Sasuke – 2 shown
Map
The specifics of where this treasure can be found
Notes
Flying Fortress 3F Found in a chest in the western room
Temple of Chaos Past B2 Found in a chest at the end of the southwest passage
Venom Blade Excalibur

Related

Katana

Sprite
Damage 33
Crit 19%
Hit +35%
V. 30,000 G

Equipped By

Found In Floating Castle 3F, Temple of Fiends Past B2
The Katana is the best Weapon a NINJA can use, other than the Masmune. It's not a huge upgrade over the Sun Sword and Defense, but every little bit helps. This sword is intended to have a very high crit rate like the Vorpal, but due to the same bug that makes the Vorpal pointless, this is not actually the case. Oddly, you can find a second Katana in the Temple of Fiends Past.