Fate/Grand Order: Fujimaru Ritsuka wa Wakaranai

Fate/Grand Order 藤丸立香はわからない

Ritsuka Fujimaru—humanity's last master. It would not have been possible to restore humanity without him. However, he does have a shortcoming... he is far too honest! A slapstick comedy in which Fujimaru's simple questions sway the heroic spirits!

(Source: MAL News)

Note: Contains spoilers for Fate/Grand Order part 2.