When Zexion sends Sora into his book world he's basically changing the world the same way Xigbar does with his space warping powers where he changes the platform you fight him on. Hacking either of these characters outside their original boss arena's can cause strange things to happen throughout different Worlds in the game. So here's a video showing just some of the weird shit that occurs when that happens.
This is the last video where we see Sora fly out of a bottomless pit, have a battle in an elevator and Saix's rooms is apparently really glitchy. Unfortunately Zexion doesn't work very well during the final boss so I couldn't show that, which is a shame.
Music:
The Real Man (Cowboy Bebop)
Stage 2-3 Ashnay (Guilty Gear Judgment)
Hand-in-Hand Fight (DBZ Budokai 3)
Running to Victory (DBZ Budokai)
...
https://www.youtube.com/watch?v=4obLvTm0qRA
I can't believe I missed that trail of rings at the beginning of Sonic's segment three times in a row.
Normal: 0:00
Hard: 10:43
Very Hard: 23:30
Music:
Titanic Plain
High and Broken
The Out of the World
Communication
...
https://www.youtube.com/watch?v=2k5Y2hbuwxU