Light Novel Accel World Vol. 16: Snow White's Slumber
After receiving the archangel Metron's blessing, Haruyuki sets off with Takumu, Chiyuri, and Blood Leopard still determined to fulfill his vow to save Nico from imprisonment. When they charge into the Acceleration Research Society's main base, they overcome several obstacles and eventually face off against Black Vise and Argon Array! But the moment they think the true fight is beginning, a mysterious red light descends, heralding the birth of Disaster Armor Mk. 2!!