A possible concise summary is:
The video is about the mystery of the box in FNaF 4, which the creator claims to have solved after analyzing clues from FNaF 6 and FNaF World. He argues that the box has changed its meaning and contents three times throughout the series, and that the final answer is that the box represents Henry's trap in FNaF 6, where five animatronics are lured and burned together. He also mentions that he will cover Midnight Motorist and the Lorekeeper graves in a future episode.
Here are the key facts extracted from the text:
1. FNaF 4 was released on July 23rd, 2015 and had a mysterious box ending that Scott considered opening in a Halloween update.
2. Scott decided not to open the box because he felt that the story of FNaF 4 was hidden and special, and that the box contained the pieces put together.
3. FNaF World was released on January 21st, 2016 and had a secret quest that involved leaving breadcrumbs for the bite victim to find in FNaF 3.
4. FNaF World also had a texture of FNaF 4's box opened in its code, but it was never used in the game.
5. Scott was dissatisfied with FNaF World and retconned its story to focus on Sister Location and FNaF 6, which introduced new characters and lore.
6. FNaF 6 was released on December 4th, 2017 and had a true ending where Henry trapped and burned five animatronics in a pizzeria simulator.
7. The pizzeria simulator was shaped like a box and could be seen as Scott's final nod to the mystery of the box, which symbolized the franchise's final climactic moment.
8. Candy Cadet in FNaF 6 told three stories that all involved five things becoming one and being put in a box, which paralleled the fate of the animatronics in the true ending.
9. The video is a Game Theory episode by MatPat, who analyzed the mystery of the box and its possible meanings throughout the series.