Soul Edge (Complete)

From the Soulcalibur Wiki

Soul Edge, after recovering all of its fragments and becoming whole once more. Even after covering the entire world in darkness, it is safe to assume that it has not come close to reaching the limits of its terrible power. At this point, it is not certain whether even Soul Calibur could stand against it. It can only be described as ultimate.

Soul Edge (Complete) is the so called, "complete form of the sword", and it has been redesigned three times in the series. In Soulcalibur II, when wielded by Nightmare, it looks like a reddened version of the original one-eye version, except with teeth, flesh and an abundant amount of eyes cover its surface, making it the most grotesque version thus far in the series. In Soulcalibur III, it lacks his eye, and is a brown sword with horns and teeth. This version is used by Night Terror and later appears as Nightmare's player two weapon in Soulcalibur IV. In Soulcalibur IV, a completely new version of the sword, itself, is created for the game, and it is used by Nightmare as his primary weapon.