Ep 21. Testament (Learning Device)

A Certain Magical Index season 2 episode 21, titled "Testament (Learning Device)," follows Kamijo and his friends as they are forced to make difficult decisions in order to stop the city from falling into chaos. The city's magical network is being destroyed, and Kamijo discovers that one of his friends may be responsible for the destruction. Meanwhile, a new powerful enemy known as the "Magic God" has appeared, and threatens to destroy everything in its path.

As Kamijo and his friends search for a way to stop the destruction, they come into conflict with various factions who all vying for control of the city. The situation is made even more complicated by the fact that some of Kamijo's friends are caught in the middle of these conflicts, and must choose between duty and personal loyalty.

Despite these challenges, Kamijo refuses to give up and uses his knowledge of the city's magical network to find a way to stop the destruction. Meanwhile, Index and other students from the Academy City join forces to help Kamijo and his friends in their fight against the Magic God.

"Testament (Learning Device)" is a thrilling episode that showcases the dangers and complexities of the magical world of A Certain Magical Index. It is an episode that will keep viewers on the edge of their seats as they watch Kamijo and his friends make difficult decisions in their fight to save their city.