Fate/Prototype is a digest version of Kinoko Nasu's original version of Fate/stay night that he developed as a novel in high school before completely redesigning it as a visual novel. It is a twelve minute anime segment released with Carnival Phantasm Season 3, and included the Prototype Material databook. There are no current plans to develop any more pieces of media based on the concept.^[1]

Plot

It will follow the original main characters, Ayaka Sajyou and Saber, before they were changed to Shirou Emiya and Saber. Unlike from Fate/stay-night, the Prototype version had master that possessed their "Master Degree", which are named following the angelic hierarchy starting from the 7th Order and up (so Princes, Powers, Virtues, Dominions, Thrones, Cherubim, Seraphim)

Master (with Master Degrees and Servant)

• Ayaka Sajyou - Voiced by Kana Hanazawa (The Seventh, Princes. Servant: Saber)
•  ??? (The Sixth, Powers, Servant: ???)
• Skyscraper Owner (The Fifth, Virtues, Servant: Archer)
• ??? (The Fourth, Dominions, Servant: ???)
• Rider's Master - Voiced by Megumi Ogata (The Third, Thrones, Servant: Rider)
• Misaya Reiroukan - Voiced by Chiwa Saitō (The Second, Cherubim, Servant: Lancer)
• Sancraid Phahn - Voiced by Takehito Koyasu (VOID, Absence, Servant: Berserker)
• Manaka Sajyou - Voiced by Aki Toyosaki (The First, Seraphim, Servant: Beast)

Other Characters

• Sajyou's Father - Voiced by Hiroki Tōchi
• Beast - The Beast is the Servant of Manaka, which is the 666th Beast in the The Apocalypse of John of Patmos and the manifestation of the sins and desire of men. The complete materialization of the Beast is the entire purpose of the Heaven's Feel system. It is similar to the concept of Avenger.

References

1. ↑ http://www.animenewsnetwork.com/news/2011-12-29/carnival-phantasm-3rd-season-includes-fate/prototype