It's a Grimoire in Campione!
Godou uses this Grimoire to steal a god's ability. So far, he used it to steal Verethragna's Golden Sword. Before he used the book, it contains the avatar, white horse, which is one of the many avatars of the Ten Avatars.
Homemade Movies take a well known scene or trailer and convert it to a homemade look. Check out how their work compares to the original and some behind the scenes of how they do it all.
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