Fate/Grand Order: Imperium Of Mankind In The Great Crusade.

After the Fuyuki holy grail war and During the great Crusade just before finding his 20 sons the Primarchs, strange anomalies is dedicated by the imperium as space and time suddenly rip apart. As submarine/spaceship appeared out of nowhere. While that's happening servants were send in different planet were the infants Primarchs landed. They will protect Primarchs as they mature.