Ancient Castle Event Alteration

I am trying to swap Terra for Celes at the diary event with the help of the  EventScriptTxt file. I found the event in question and replace actor $00 (Terra) for $06 (Celes) in four instances: CC/1F08 (C2108 for HxD), CC/1F1D (C211D for HxD), CC/1F26 (C2126 for HxD), and CC/1F39 (C2139 for HxD). Now, the event doesn't play. I've look over the event within the document and not seeing anything else to alter, there is something else, but I am not seeing it. I decided to check out the event with Terra in the party without Celes. The event stars, but Terra's sprite is not present during the "separation" of the party while the other party members are present and the game soft blocks right after, this happens before the textbox is suppose to appear. I can't figure out how to complete the diary event with Celes. Anyone has any ideas?

At CC/1EF8 there is a C0 command to check the event bit $1A0. This event bit checks if Terra is in the party because DE was the previous command. If Terra is in the party, the extra cutscene runs, and if she isn't then it won't. You need to change it to check bit $1A6 instead to check if Celes is in the party. Otherwise, the cutscene will decide to run when it shouldn't.