CARDFIGHT!! VANGUARD MOVIE: NEON MESSIAH

After the events of Link Joker-hen, Takuto Tatsunagi announced an invite-only tournament in a dream, and invited both Aichi and Kai to take part in "Messiah Scramble". The prize being the card named "Messiah", the name of a saviour that was heard in a dream. At the same time, there were many incidents of units disappearing from Vanguard cards throughout the world. Aichi and Kai team up to a confront an enemy that threatens the peace they've just regained. The movie is a prequel to Legion, leading up to Aichi's disappearance. — Description from AniList community (anilist.co).