Mutsunokami

Mutsonokami is a recurring weapon in the series. It is often the most powerful Katana in each of the games it appears in, though it did not start appearing until the Advance remakes of the earlier games.

Final Fantasy IV
Mutsonokami is the strongest katana in the game, only appearing in the Advance remake, and can only be used by Edge. It has an Attack of 100, Accuracy of 45, and grants +10 Strength and Speed. It is found at the Lunar Ruins.

Final Fantasy IV: The After Years
Mutsonokami is the strongest katana in The After Years. It is found in the chest that is left behind after the player defeats the Ghost Train in the Depths.

Final Fantasy V
Mutsunokami is the strongest katana in the Advance remake, and is found in the Shadowed Gate section of Lethe Court. It has an Attack power of 139, and can only be used by Freelancers, Samurais, and Gladiators.

Final Fantasy VI
Originally translated as Sky Render, Mutsonokami is the second strongest katana in the game, used only by Cyan. It can be won from Fiend or by betting the Aura Lance in the Colosseum. It has an Attack power of 215 and increases Evade by 20%.

Final Fantasy VII
Mutsunokami Yoshiyuki is the Japanese name of the Yoshoyuki sword. It is a mid-powered weapon for Cloud, and has an Attack power of 56 with two single Materia slots. Its power increases if one or both of the other party members are dead.

Etymology
The Mutsukami Yoshiyuki is the name of Sakamoto Ryoma's favorite katanas, and is a family heirloom.