The primary weapon in Cloud Strife's set of interlocking swords from the Compilation of Final Fantasy VII, namely Advent Children.
On its own, it is a wide, double-edged sword with gaps in the middle. As part of the fusion swords, the middle is collapsed, making the blade thinner.
In Shinzui's personifications, the "First Ken" is differentiated by a silver/gray color scheme, jagged jacket edges, and a sparsely clothed torso.