Delightworks revealed two new Servants that will appear in the Japanese version of F/GO when the Tunguska Sanctuary event launches. This news came during the Chaldea Satellite Station 2021-2022 (Fukuoka) event. Both Servants will be of the Rider class, with one SSR and one SR. There is no news as to whether or not they will enter the story gacha after Tunguska Sanctuary ends. [Thanks, Famitsu!]
The SSR Rider who will appear in Fate/Grand Order is Jiang Ziya, a Chinese noble and strategist. According to his introduction text, he is a professional when it comes to killing beasts. His Noble Phantasm will hit all enemies on the field. Meanwhile, the SR Rider is Dobrynya Nikitich, who is a knight of Rus folklore. She appears as a female Servant and is a dragon slayer. Like Jiang Ziya, she has a Noble Phantasm that hits all enemies.
Both of the new Riders in F/GO will likely play a role in the Tunguska Sanctuary event. According to the introduction blurb, Tunguska Sanctuary is canonically right after Lostbelt 6. After Koyanskaya flees from the Lostbelt, Chaldea chases after her, deeming her a threat. Tunguska Sanctuary will have a total of four raid battles, taking place over the course of December 23 to 27, 2021.
Though the first raid opens on December 23, the event will officially start on December 22, 2021. Players will need to have finished Lostbelt 6 before they can access this event. However, even if you cannot play the event, you will be able to pull on the banner.
You can view the Tunguska Sanctuary commercial here:
Fate/Grand Order is available on mobile devices worldwide. Tunguska Sanctuary, as well as Jiang Ziya and Dobrynya Nikitich, will debut on the Japanese server from December 22, 2021.