X: Vol.4 (2002)

Episodes 13-16 of the Japanese anime series. Kamui Shirou and Fuuma Monou have been best friends since childhood, but they are separated after the mysterious death of Fuuma's mother. Six years later, their destinies collide once more when Kamui returns to Tokyo to fulfill his destiny as leader of the Dragons of Heaven, and protect the future of mankind from the human-hating Angels of Earth. Episodes are: 'Return', 'Gathering', 'Guardian' and 'Slaughter'.