Sword Art Online: Hollow Realization Vol. 5 (manga)

Despite being identical, Premiere and Tia are actually polar opposites and-even worse-enemies. After learning of the sisters' unprecedented potential for world destruction, Kirito and the gang are forced to put their quest on hold in fear of losing their beloved Ainground and its NPCs. Meanwhile, Genesis, seeking to tap into the twin goddess's powers, challenges Kirito to a battle for Premiere! Which black swordsman will emerge victorious?!