Within the altered history of the Seventh Singularity in 2655 BC, the gatekeeper is a soldier watching over the entrance to Uruk. Ritsuka Fujimaru, Mash Kyrielight, Medusa, and Merlin encounter him upon arriving to Uruk, the gatekeeper taking special notice of Medusa, believing her to be an ordinary child. Offering her candy given to him by his daughter, Medusa reluctantly accepts it.

A seventh Singularity has been discovered in ancient Mesopotamia in the year 2655 B.C. 
 
The land of Uruk, governed by the wise King Gilgamesh after he returned from his quest for immortality, was grand and prosperous until three goddesses and countless Demonic Beasts appeared. These enemies have brought Uruk to the brink of destruction. With a Rayshift—a method of traveling across both time and space—Fujimaru and Mash journey to the land of Uruk, where they encounter the fortress city of Uruk and the Absolute Demonic Front, where a terrible battle against the fearsome onslaught of the Demonic Beasts rages. There, the citizens of Uruk, who live their lives to the fullest despite facing an existential threat, continue to fight for their future. Deities and Demonic Beasts attack with terrifying force, and mankind pushes back with all its might... This is the era where humans and gods are destined to part ways. 
 
Fujimaru and Mash, the pair who have fought through all six previous Singularities, embark on their final battle. 
 
(Source: Aniplex of America) 
 
Note: Based on the Babylonia Singularity of Fate/Grand Order, the Japanese smartphone role-playing game created by Delight Works based on the Fate series by Type-Moon.

"The human race will become extinct in 2017." The Chaldea organization, an organization charged with preserving the future of humanity, observes a singularity. To solve it, Rika Fujimaru and Mash Kyrielight will be transported to the city of Fuyuki in 2004. The battle for the future of humanity has begun.
 
(Source: Anime News Network)
 
Note: This manga adapts the first, third, fifth, seventh and final singularity from Part 1 of Fate/Grand Order.

Monban