Rider's True Name is Ivan Groznyi (Ivan the Terrible) (イヴァン雷帝, Ivan Raitei?), also called the Thunderous Emperor (雷帝, Raitei?), the alternate world Lostbelt version from the Anastasia Lostbelt. As of the time of the Lostbelt, he had ruled as Tsar of Russia for nearly 450 years into present day 2018 AD of the Lostbelt, and later registered as a Servant of Chaldea after the Lostbelt was destroyed.
The history of Ivan's Lostbelt diverged from that of Greater History of Man in 1570 AD when an asteroid struck and plunged the world into an ice age. Most humans died, and while Russians were used to the cold and prepared for such weather, 90% of their population perished and they were on the cusp of extinction. Ivan and his mages were able to save the country by combining humans with magical beasts, creating the Yaga, with Ivan himself becoming the first.
Anastasia: Permafrost Empire
The still living Ivan is present in the Lostbelt as its King, currently sleeping due to Mozart playing his music under the command of Kadoc Zemlupus. Anastasia utilizes Ivan's Oprichniki soldiers produced by his Noble Phantasm to attack and subdue Chaldea Security Organization with Koyanskaya and Rasputin.
As a Yaga, he has merged with mammoths and saber tooth tigers. He constantly evolves and grows while sleeping, and after 450 years has arrived at the level of a Divine Beast. The Crypters say he is on the level of a Divine Spirit when comparing him to the Kings of other Lostbelts. Atalanta Alter states that his form is similar to that of what an Olympian god may look like based on her knowledge. Avicebron says "That is a Prime One from an ancient age before there were humans on this planet."
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 Fate/Grand Order - Ivan Groznyi (Rider) Profile
- ↑ Fate/Grand Order: Cosmos in the Lostbelt - Anastasia: Permafrost Empire, Chapter 1
- ↑ 3.0 3.1 Fate/Grand Order: Cosmos in the Lostbelt - Anastasia: Permafrost Empire, Chapter 21