1x11 - dot hack Legend of the Twilight

Morti demonstrates her power as an AI and begins the final battle using NPC's. Both the adventurers and the admin (Reki and Kamui) figure out the real meaning to Morti's actions at the same time. Morti starts using a special monster that creates a virus to infect the player character data. While the adventurers start fighting the monster, the rest of "The World" begins experiencing problems.