Horsemen of the Apocalypse

The Horsemen of the Apocalypse, also known as the Horsemen of John, are monsters that suddenly appeared in the year 2012 at the time of the disaster. They get weakened by the barrier raised around the walls. They get rapidly stronger when they’re more than a kilometer away from the barrier.

Details
The Horsemen are a form of chimera, and were originally created from experiments by the Hyakuya Church. Horsemen are usually large creatures with wings and humanoid-animal like bodies. They prey on any creature that they come upon, human or vampire.

Story
Yūichirō Hyakuya encountered a Horseman of the Apocalypse during an expedition. Despite being ordered to run, he disobeyed orders and attacked the monster, as a result he gets punished for insubordination.

When arriving at Harajuku station, the Moon Demon Squad spotted a young girl being chased by a Horseman of the Apocalypse. Shiho was the one who'd slain the Horseman whilst Yuichiro was unintentionally used as bait.