Armament Full Control Art

Armament Full Control Art is a super high-ranking Sacred Arts ritual that is used to awaken the attributes of a Divine Instrument-class weapon, inherited from their base material. The ritual is divided into two phases, the «strengthening» and the «releasing» phases.

Strengthening Phase
According to Cardinal, strengthening refers to partially awakening the weapon's memories and manifesting a new offensive ability. It is the aforementioned strengthening phase. First seen in the novel at the first battle after Kirito acquired his black sword in Underworld.

Releasing Phase
And for releasing, as the term suggests, it awakens all of the weapon's memories, releasing its rampaging power.

Trivia

 * In the web version, the Armament Full Control art only consisted of the second, releasing, phase.